Original subtitles

New York, famed throughout the world as a beacon of opportunity,

HQ of capitalism.

A gleaming, brash, technological marvel, where anything is possible

and everything has its price.

New York City is the ultimate embodiment of the American dream,

but for the millions of poor immigrants that arrived here

in the 19th century, it was more of a nightmare.

150 years ago, New York covered only the southern tip of the island of Manhattan.

In the throes of its Industrial Revolution,

the city had become one of the most

disgusting and filthy places on earth.

New York was a corrupt frontier city, where poor immigrants

were ruthlessly exploited by fat-cat bosses and greedy landlords,

all driven by the pursuit of filthy money.

The Big Apple was rotten to its core, but it was the fight against filth,

the struggle against grime and crime, that would shape almost every aspect of this city.

I'm going to explore what New York was like at its very worst.

I'll meet the parasites that preyed on its citizens.

Ooh, ow, that just bit me.

And I'll get my hands dirty, to find out just how close

this city came to drowning in a sea of its own detritus.

What the heck is this?

You tell me. Is that urine?

I think that could be urine.

Yet, out of its nightmare of filth, New York's iconic skyline would be forged.

In just 100 years, the city's population shot up by a staggering 1000%.

And to survive and continue to prosper, New York had to clean up its act.

Pioneering reformers and inventors would lead the fight,

with momentous engineering projects and many revolutionary ideas.

The electric light bulb.

From the world's first commercial power station to the earliest automobiles.

Bringing her round.

IMITATES SQUEAKING BRAKES

But it's only now in the 21st century,

that we're beginning to realise that New York's battle

to transform itself into a modern city would come at a price.

New York. Today it's home to more than eight million people,

the biggest and richest city in the United States.

Built within easy reach of the Atlantic trade routes,

for nearly 400 years New York has been the bridge

between Europe and North America.

New York's success was always based on trade.

It's a wonderful natural harbour, where ships from around the world can anchor safely.

You have the city on Manhattan Island and the Hudson River,

which reaches deep into the heart of the continent.

This is the gateway to North America, the link between the New World and the Old.

Early in the 19th century, New York was being transformed by the Industrial Revolution.

Its shores were lined with factories and workshops.

Up town, the city's elite lived in some of the grandest town houses in America.

New York was a city where serious money could be made.

It had quickly become a magnet for millions of European immigrants,

all drawn here to make their fortunes in the land of opportunity.

It was the start of one of the biggest mass migrations in history,

as people fled abject poverty, religious and ethnic persecution.

The first to arrive in great numbers were the Irish,

as they fled the great potato famine of the 1840s.

Over 650,000 Irish would come to New York.

Many migrants were destitute before they left

and were unable to survive the terrible conditions on board.

As many as a third of them died.

Despite the horrific death toll on some of the ships,

at its peak in 1845, up to 1,000 Irish immigrants a day were landing in New York.

But for many of the survivors, the worst was yet to come.

And this is where many of those poor immigrants ended up.

It's now an area just between Chinatown and Little Italy in Lower Manhattan.

Back then it was known as the Five Points,

because it was the intersection of five big roads.

Then it was a terrible, infamous slum.

25,000 people packed into buildings with no central heating, no running water and no sewers.

The streets of the Five Points were piled high

with rubbish and animal waste.

And in New York's cold winters, this toxic mix would freeze.

This is how bad it could get.

In the winter, layer upon layer of frozen muck would pile up,

until in some streets it was a metre and a half deep.

New Yorkers fondly called this "corporation pudding".

It was a terrible mixture of human and animal excrement, waste products

from slaughter houses, breweries and tanneries,

and all the muck and mud from the streets.

For months at a time during the winter,

this would have clogged the streets.

It wasn't only disgusting streets newly arrived immigrants had to contend with.

The tenements they had to live in were just as bad.

Vast swathes of New York slums were owned by the wealthiest families in America,

and they were making a fortune from the poor immigrants.

Far from escaping the deprivations and social injustices of Europe,

these recently arrived immigrants found they were in a city that was dirtier and even more unfair.

Employed by the landlords, it was the job of runners to hustle

freshly arrived immigrants into the tenements,

where they would be fleeced to pay an extortionate rent.

Now a museum, this is one of the last tenement blocks in the city

that has remained pretty much unchanged since the 19th century.

These rooms might feel quite nice and spacious

and when they were built, they were.

With so many immigrants arriving,

building large, six-storey tenement buildings seemed like the perfect solution to the problem

of how to house this expanding population.

But with so many new immigrants arriving,

demand rapidly outstripped supply,

and the slum landlords spotted the chance to make some filthy money.

Rents shot up, and some apartments like this could have had two families living in them.

There could easily have been a dozen people in here.

These tiny apartments rapidly degenerated

as more and more people were piled in.

With the landlords charging such high rents,

soon these apartments were more than just homes.

They'd also have to double up as a workplace.

This room would have been a sweatshop,

with five or six people in here making clothes, shoes and hats,

and at night, it just would have been a cramped dormitory.

No running water, no bathrooms,

and just three stinking privies shared by hundreds.

This place was more than unhygienic.

And as if that wasn't enough, there were reports of some immigrants

keeping their animals in their apartments.

These corridors would have been filled with a dizzying array of smells

and the discordant hubbub of languages from all over the world.

And, of course, this melting pot was also the perfect breeding ground for disease.

Overcrowded and filthy, early in the 19th century,

New York slums were ravaged by a series of devastating epidemics.

But the city's elite were often reluctant to act

until they themselves were threatened.

In 1832, an outbreak of cholera, a deadly waterborne bacterium,

had spread through the slums and infected the whole city.

So many people died that bodies piled up in the streets,

and it was said that anyone with a horse was drafted to help move them.

Over 3,500 New Yorkers, both rich and poor, died in the epidemic.

But it wasn't just disease that was devastating New York.

At around the same time, 50 acres of the city were destroyed in an inferno.

Fire and deadly disease

were threatening its industrial expansion.

New York needed to invest heavily to secure a plentiful supply of this.

Fresh water.

Back in the 19th century,

people would have killed to have this much fresh water

delivered reliably into the heart of New York City.

That's because Manhattan was very marshy.

It was very hard to dig wells that would produce

anything other than brackish water,

so lots of people relied on very few wells.

It also meant that porous soil,

and all the human and animal waste would seep down and pollute the fresh water,

and that's how disease spread, that's how people got cholera, and epidemics broke out.

In 1837, the city embarked on America's biggest ever engineering project -

to get millions and millions of gallons of fresh water into New York every day.

And this is where they got it from - they dammed the Croton River, north of New York.

This dam was actually built in 1906.

The original is now submerged under the reservoir.

But that reservoir was still big enough to hold hundreds of millions of gallons of fresh water.

You get a sense of the size of this operation from over here.

It's just vast. It shows the amount of water that a modern city needs

to survive and prosper.

To get all this water to New York City, 41 miles away,

they built an equally impressive aqueduct.

Large parts of the aqueduct survive right to the present day,

and there's a big stretch of it right here underneath my feet.

And over here is where I get in.

The Croton Aqueduct served New York for over a century.

It was finally decommissioned in 1955, which means I can get inside it.

New York's first aqueduct would take more than five years to build.

It cost over 14 million, which means at the time

it was the most expensive construction project in America.

It took about 4,000 workers, mostly Irish, to build this tunnel,

eight feet high and over seven feet wide.

It loses exactly 13 and a quarter inches for every mile that it travels,

and that means that the gravity brings the water from the reservoir, which is up there,

right the way down there towards New York City, 41 miles away.

35 million gallons a day,

and it took 22 hours to make that journey.

When it was completed in 1842,

you could ride on a boat all the way to New York in this tunnel.

So this was the last section to be built,

channelling the water up this seven-foot iron pipe,

right across the last obstacle before the city - the Harlem River.

Right, this should be the place to get a sense of the scale.

This is the High Bridge, a truly epic piece of 19th-century engineering,

spanning a quarter of a mile and rising 100 feet above the river.

The Croton Aqueduct marked the city's first major step towards modernity.

When the water started flowing, New Yorkers rejoiced

with a Festival Of Connection, which included special drinks, songs and a huge procession.

One New York diarist wrote

that "nothing is talked about or thought about in New York City, but Croton water."

The Croton Aqueduct would bring fresh water...

and a fresh problem for the city.

The first to benefit from the new water system were the rich.

They now had even easier ways to keep clean.

And it was really good news for plumbers,

who got to install 6,000 indoor bathrooms for the people of New York.

The Croton Aqueduct also proved to be good news for a whole host of other industries,

manufacturing things like taps, toiletries

and, of course, toilets.

It was also very good news for one New Yorker called Joseph Gayetty,

who in 1857 invented toilet paper,

which gave the filthy rich something else to flush down their new toilets

with all that Croton water.

With 6,000 homes now connected up to the Croton Aqueduct,

that was a lot of waste water that was produced, especially when all those toilets got flushed.

Much of it ended up on the streets

and flooding the basements of nice houses like this.

The solution was to build some of these - sewers. And they did,

building some of New York's first.

The trouble is these are very expensive,

and the landlords in the slum areas couldn't or wouldn't pay for them,

and that left the residents of those areas wallowing in their own filth.

Although the Croton Aqueduct did bring fresh water into the slums,

there the rich landlords refused to pay for indoor plumbing,

or even connect to the sewage system.

The poor were left with stinking privies that would flood into the streets.

In fact, with ever more immigrants arriving all the time,

the slums became even filthier,

which for some new arrivals was heaven.

The slum landlords weren't the only ones feeding off the poor immigrants.

In the bowels of New York's Museum Of Natural History,

Louis Sorkin has been pursuing his passion for the insects

that thrived in 19th-century New York,

like these blood-sucking bed bugs.

There's one. I can see it.

These are adult bed bugs,

and that one's moving off. Ah, it just bit me, straightaway.

It'll take a few minutes to fill up on blood.

Millions of bed bugs would have hitched a ride across the Atlantic

with unsuspecting immigrants.

Although they didn't transmit disease,

their painful bites can easily become infected.

This one's pretty full already.

This one's full already?

See? And that one's full already.

That's... They're full on MY blood.

That little one's swollen to about three times the size already.

Yeah, that can go to three to five times its volume,

filling with blood.

Bugs have a bad reputation though.

That's true. Many people just don't like them.

But once you get to know them, they grow on you.

Grow on me quite literally in fact.

Look at that guy - he's gone completely red now.

Uh-huh, that's true.

So I'm not getting disease from these guys.

Which ones were in 19th-century New York that do spread disease?

Well, body lice.

Have you got some of those?

Yes, I do, actually. I thought you might.

Body lice proved to be fatal in the slums.

They carried typhus, a particularly nasty disease.

Its symptoms include a rash,

delirium and a fever so debilitating

that more than half of those infected

die within two weeks of being bitten.

These are human body lice.

And what conditions do these need to sort of breed in and prosper?

Usually it's just overcrowding.

When you get many people all stuck, you know, in very crowded conditions,

the lice will crawl from one person to another, to another.

If they were infesting your clothing, which is normally what happens,

then you could have 50,000, 70,000 lice could be there.

The typhus bacteria live in the guts of the lice.

But surprisingly, it's not their bites that actually transmit the disease.

Although it looks pretty dangerous, it's not biting the human that spreads disease,

it's actually what's coming out the other end? Yes, that's correct.

The blood is taken up, but the disease organisms are developed inside the gut of the louse

and then defecation occurs, and your disease organisms are now in that,

and the person scratches it into the wound.

New York's poor were unaware that they were giving themselves typhus

as they scratched the infected excrement of the lice into their fresh bite wounds.

In the mid 1850s, the city not only lacked the scientific knowledge,

but it saw little financial incentive to do anything about its disease-ridden slums.

For every immigrant that died, there would be a new arrival, hungry for work and a place to live.

New Yorkers were being decimated by wave after wave of disease.

In fact, more New Yorkers were dying than were being born,

and if it wasn't for all the immigration, said one city inspector,

the city would soon become depopulated.

In fact, in many parts of New York, the death rate was twice the American average.

Then in 1852, one young doctor decided it was time to get to grips

with the city's endemic filth and epidemic injustice.

Doctor Stephen Smith was horrified to discover

many of his typhus patients had something else in common.

They all lived at the same address, in the same stinking tenement building.

Inside, Smith was appalled to see

so many diseased immigrants crammed into one disgusting building.

He wrote, "The whole establishment was reeking with filth, and the atmosphere was heavy

"with the sickening odour of the deadly typhus, which reigned supreme in every room."

Enraged by what he'd witnessed, Smith stormed off to confront the slum landlord.

By consulting the tax records, Smith tracked the slumlord down.

He turned out to be a man of considerable wealth and influence.

Despite Smith's angry protests,

the landlord initially refused point blank

to improve conditions for the residents.

Smith started campaigning to legally force New York's wealthy landlords to clean up their slums,

but he soon discovered that getting the law changed was not going to be easy.

New York's entire system of government was beset by sleaze,

and one place symbolised this more than any other.

This was the New York County Courthouse.

It was supposed to be devoted to the administration of fair and impartial justice,

but in fact it became a symbol of filthy corruption.

This courthouse, grand though it is,

at the time cost New York's tax payers

a staggering 12 million,

almost twice the amount that the USA paid Russia for Alaska a few years later.

The man in charge, William "Boss" Tweed,

headed the infamously corrupt Tammany Hall Political Machine

and was stealing millions of dollars from the city.

Corruption was endemic, and it was thanks to men like Boss Tweed

that these guys were being left to clean the streets.

Even though New Yorkers were paying for basic services like street cleaning,

a large proportion of the cash was just being pocketed,

which left large parts of the city looking like a rubbish dump.

So the only people that could be trusted

were those who would do it for free.

In slum areas like this, pigs were eating tonnes of rubbish every year.

Boss Tweed and his mates are estimated to have embezzled around 200 million.

That's well over 1 billion today, and that's just greedy.

Faced with corrupt politicians and filthy rich landlords,

for a decade Dr Stephen Smith's campaign to improve the lives of New York's poorest had got nowhere.

Then, in 1865, there were reports that a fresh outbreak of cholera,

a deadly waterborne disease, was on its way from Europe.

Smith knew that the epidemic would take hold in the slums and spread like wildfire across the city.

Smith had already spelled out the dangers

in a damning report published earlier that year.

An original copy of it is kept here in the library of the New York Academy of Medicine.

This is it, it's the 1865 Citizens' Association Report On The Sanitary Condition Of The City.

It lists, ward by ward, everything that is filthy about New York City,

from rotting horses in the streets to sewage in the drinking water.

In the front of the book is a letter signed by prominent reformers,

including - look here - Stephen Smith.

And they advocate strongly that the city should introduce

the kind of sanitation system that London had.

This could not be more pressing, say these reformers,

because the total number of deaths in the city of New York during the year of 1863 was 25,196.

That is equal to one death in every 35 of the inhabitants, and that was an unacceptably high number.

For the first time, the authorities were forced to recognise just how filthy New York had become.

They also produced these maps that covered the whole city,

going into every single property in incredible detail.

This is the infamous Five Points area,

and there's a key down the left-hand side here

that labels stables, and privies and private dwellings.

One of the most important symbols here is the black square.

These are privies "in an extremely offensive condition."

I've spotted one block next to the brewery and the Mariner's Church,

where there are several privies in extremely offensive condition.

That is a block where you would not have wanted to get caught short.

The report and the imminent arrival of cholera

finally frightened the city into action.

It established America's first independent board of health,

and gave Dr Stephen Smith a job of vital importance -

stopping cholera from decimating New York again.

Smith's solution was simple.

He wanted to clear out the slums.

I've come to this 19th-century tenement building,

because this apartment apparently hasn't been cleaned for 50 years.

It's going to give me a sense of just how much filth Smith had to deal with.

Wow! HE COUGHS

Oh, the smell's unbelievable!

The elderly lady who has lived here for 60 years suffers from depression.

She was found collapsed on the floor and taken to hospital.

I mean, clearly this is one old woman's apartment that hasn't been cleaned since the 1960s.

When you come in here, you realise humans fight a never-ending battle against our own waste,

and in modern cities we're winning that battle.

But this is a reminder that that filth can overwhelm us, and ultimately destroy us.

And you get a real sense in here of the kind of conditions that Smith would have been dealing with.

New York in the 19th century was a city labouring under tonnes of filth,

accumulated mess from years, like this.

With the imminent arrival of cholera,

under Smith's control the Metropolitan Board of Health

set about mobilising an army of cleaners to get to grips with the city's grime.

You got your mask on? Yep.

All right, you ready? Let's roll.

Nearly a century and a half later, this team of specialist cleaners are about to do the same,

and try to make this apartment habitable once more.

So we just start right here, OK?

What the heck is this?

You tell me. Is that urine?

I think that could be urine. You think it's urine?

That is disgusting.

The first six months of 1866 alone, the health orders went out from the Metropolitan Board

to remove 160,000 tonnes of manure from the streets.

Over 38,000 cartloads of night soil. That's human excrement.

103 dead horses were removed and over 3,800 dead cats and dogs.

This was a cleanup effort on a monumental scale.

Crucially, where cholera was reported,

Smith ensured that residents were put in quarantine

and the house thoroughly disinfected.

See all these roaches in here?

They're German. Those are German.

German roaches? German roaches.

Smith's work was an unqualified success.

Cholera did reach New York, but only 591 people died in the outbreak.

That's ten times less than the previous outbreak, 17 years before.

New Yorkers were starting to realise that connection between dirt and disease,

and the city could turn its attention

to an industry with the capacity to make New Yorker's really sick.

Food.

Some of New York's most famous foods had their dirty little secrets.

Take hot dogs for example.

Can I have mustard and onions, please? Sure.

There were some scandalous things happening at the city's sausage industry.

With so many people living in New York, some profit-hungry butchers

had found a way to feed them rotten pigs' heads,

decaying hearts and slime-covered steaks.

Oh yeah, there you go, there you go. It's...

DAN COUGHS

Oh, that is disgusting!

With no refrigerators, unsold meat in backstreet butchers would quickly rot,

but some weren't prepared to throw it away and lose money.

You know, you killed about a million pigs a year

in New York City, 1880s, and you made your hams, bacon and all that.

But you got the other stuff.

You got the heads, you got the hearts, you got the lungs.

What are you going to do with it?

You paid for it, you want to use it, so you turn it into sausage.

In 1874, one sausage-making butcher

was caught with 220 rotting heads in his cellar.

Oh, man. That is just disgusting.

The slime and foul smell of this three-week-old meat

comes from the bacteria that form on its surface

and start to break down the flesh.

It's funny, it feels like it's kind of rotting away,

that the layer of scum's coming up through your fingers.

That's right. That's just rotting away.

For centuries, butchers could do little about the stink that made their rotten meat unsellable,

until in the 1880s, a new wonder product appeared on the market.

Borax.

Borax, you use it to clean your floors these days,

but back in the 1880s the meat companies started to add it.

We've got some right here, put a little bit of magic...

We're adding a cleaning product! There it is.

I suppose the key is just using it as a kind of masking agent, right?

That's right, you want to use it to kill that bacteria that's there.

When you kill the bacteria, you kill the smells the bacteria generates.

So you got to trick those age-old senses

using modern industrial methods, and it's not going to stink.

'Boracic acid works by killing the bacteria that make rotten meat stink,

'and it's also pretty good at disinfecting wounds,

'killing cockroaches and, of course, cleaning floors.'

There it goes.

So would this smell nicer now, then? Well, it wouldn't smell as bad, shouldn't smell as bad.

What do you think? Actually that's...much better.

But the meat is still bad, that meat is still going to get you sick if you eat that meat.

What you want to do is turn the meat from looking like that,

kind of old and gnarly, to looking like this.

'Back then, one way to give grey, rotten meat a healthy red colour

'was to add clothing dye made from coal tar.'

And this is clothes dye here? Clothes dye, yep.

'Which also sometimes had a touch of arsenic in it.'

And mix it up. Mix it up? Mix it up.

This must just rot in someone's gut straight out.

'The next stage is to add some stale bread or biscuits to bind it all together,

'before pumping this chemically enhanced,

'pulverised pork mixture into pre-prepared pig's intestine.'

God. Let's make some sausage.

Just push. A little bit of air in there,

there is comes, there it comes.

Oh, my goodness, that looks like a real sausage, doesn't it? It does.

This is the size of your Italian sausage, and then what you'd do,

you'd tie off the end and you'd kind of roll it up.

There's your sausage in New York City, 1900.

I know I shouldn't, but I'm actually feeling very proud of my sausage.

The fact that it would make someone very sick or kill them, well, worry about that later.

In 1898 there were more than 25,000 food establishments in New York,

and with just ten food inspectors for the whole city...

..for years, backstreet butchers could do pretty much as they pleased.

It wasn't until 1906, when journalist Upton Sinclair exposed

the horrors of the American food industry in his book The Jungle,

that serious food regulations were finally introduced.

After that, New York became deadly serious about food hygiene.

They even locked up one cook for life for not washing her hands properly.

TOILET FLUSHES

For Irish immigrant Mary Mallon, hygiene wasn't too high on her list of priorities.

Which was unfortunate, because Mary was a cook.

By not washing her hands, Mary was unknowingly spreading typhoid.

Its symptoms included diarrhoea and a terrible fever.

Mary couldn't understand why, everywhere she worked, people kept getting sick.

WOMAN VOMITS

Some even died.

Mary had no idea that these were on her hands. Bacteria.

In 1882, German Robert Koch had published his paper

proving that these tiny micro-organisms caused disease.

It transformed medical science.

This was a groundbreaking moment.

For the first time, scientists could actually see the enemy,

and it also gave birth to a new science of microbiology,

where they discovered how different bacteria caused a host of different diseases.

In 1907, New York sanitary expert George Soper had tracked the typhoid outbreak down to Mary.

Suspecting she was immune to the disease, but still carried the bacteria,

Soper pleaded with her to be tested, but Mary angrily refused and chased him off with a fork.

STABBING VIOLIN NOTES

Soon after a visit from the Health Board, Mary found herself

locked up in quarantine, where she remained for three years, until she promised never to be a cook again.

Five years later there was another typhoid outbreak.

25 people were infected and two died.

Again, it was traced back to a single cook,

although this time it was to a Mrs Brown.

Mrs Mary Brown.

Mary had reneged on her promise.

Typhoid Mary, as she became known, was carted off to quarantine again.

This time they never let her out and she died a prisoner.

Even though science helped New York get a handle on disease control,

any efforts to clean up the slums

had been quickly overwhelmed by mammoth immigration.

The city's population had shot up 600% in just 50 years.

By the 1880s, the population of New York was 1.2 million.

Half of them were crammed into the slums.

Whilst the city's rich and powerful turned a blind eye,

corruption and exploitation

had become as ingrained as the dirt itself.

Horrified by this injustice and poverty, one New Yorker decided to make a stand,

using a new tactic to shock the entire nation,

and force the city to tackle its filth.

His name was Jacob Riis, and in 1888 he became the first American to use this, flash photography,

to expose the true horror of the slums as never before.

Using a flash, Riis was the first photographer to be able to capture

the grim reality of life inside the dark tenements.

His pictures would reveal to the nation the terrible deprivation

suffered by many of New York's poorest immigrants.

As a young man, Riis had himself lived in many of the city's worst slums.

Including the infamous Five Points that he now photographed.

And where he made his living as a crime reporter.

He embarked on a personal crusade to get things changed.

He gave a series of lectures around New York City, shocking audiences with his graphic slides.

Riis saw photography as a weapon

to fight the injustices he saw daily in the slums.

As his slide shows drew more attention, he was offered a book deal.

In 1890, Riis published a book called How The Other Half Lived.

For the first time, people could see actual images of New York City's poor.

Poverty now had a human face.

This had a seismic impact right across America

and it brought the issue to the attention of the rich and powerful.

Becoming a bestseller,

Riis's sensational book caused a national outcry.

A senate committee was convened to tackle corruption

and New York would be forced to clean up its streets and its politics.

Riis' pictures had a real and lasting impact.

They created a groundswell of support that enabled him eventually

to successfully campaign for the destruction of the Five Points.

It galvanised city politics. People turned against corrupt politicians,

and in the elections of 1895 Tammany Hall finally lost their grip on power.

A huge clean-up followed, as the new administration set about ruthlessly rooting out corruption.

Another revolution was taking place that would eventually see

New York's rubbish brought to extraordinary places like this.

Fresh from defeating yellow fever and typhoid in the South,

George E Waring took control of New York sanitation departments.

Colonel Waring, a Civil War hero, had orders to stop New York looking like a dump.

For decades, politicians and corrupt contractors

had been taking the cash and leaving the trash all over the streets.

Now Waring's big clean-up began, starting with the street cleaners themselves.

Dressed in their sparkling white uniforms, Waring's men weren't

just there to pick up rubbish, they were there to set an example.

They were banned from going into bars, from swearing,

and from being mean to their horses.

New York had never seen anything like it.

Soon those nicely treated horses

were taking tonnes of refuse to the dump,

as Waring's White Angels, as they became known,

actually did what they were paid to do,

and the city was transformed from this...

to this.

And from this...

to this.

Waring was so successful cleaning up New York City

that the President sent him to Cuba to sort out their sanitation.

Sadly, just after arriving, he contracted yellow fever and died, but he left this world,

and New York City in particular,

a cleaner place.

As the 20th century approached, it wasn't only New York's streets that would be transformed.

The Industrial Revolution was gathering pace, and famous landmarks

like the Statue of Liberty and the Brooklyn Bridge

were appearing on the city's skyline.

Meanwhile, new railroads and telegraph lines had

firmly set the city at the very heart of international trade.

In the coming years, New York would soon overtake London to become

the world's wealthiest city, and one of the most densely populated.

So many people and so much wealth would generate a mountain of filth.

To survive and prosper, New York would need to invest heavily

in new technologies.

And, with money to be made,

a new breed of entrepreneur would flock to the city.

The New York Stock Exchange was booming, money and trade was flowing

into the city, the future was looking bright for everybody.

Well, everybody that is apart from the guys at companies like the Knickerbocker Gas and Light Company.

Shares in that sector were collapsing.

Since the 1830s,

New York had been lit by a poisonous gas made from coal,

but not for much longer.

Thomas Edison had perfected a bright money-making idea

that would do away with New York's gas lamps for good.

The electric light bulb.

CHEERING

Edison argued that gas lamps were a pain to light...

LAUGHTER

..the gas was poisonous...

the fumes were noxious...

they left this horrible black staining...

LAUGHTER

..and sometimes...

they blew up.

All of which was true.

And, because Edison's light bulbs had no such problems, they were a much better way to light New York.

And, to power them, in 1882 Edison built this.

The world's first commercial power station,

sited just here off Wall Street,

burning tonnes and tonnes of coal,

not to produce gas, but electricity to light up New York.

Edison knew his power station,

belching out black smoke in the heart of the city,

could only send electricity a few short blocks.

To illuminate the whole of New York, he would need a lot of

power stations and a lot of investment from Wall Street.

Edison threw the switch at 3pm on 4th September 1882...

..and illuminated a square mile of New York,

thus beginning the city's love affair with bright lights.

Edison lit up Broadway and Wall Street.

His plans for world domination looked to be continuing apace, but at his moment of triumph

a rival turned up, a man called Nikola Tesla, who had an alternative system for distributing electricity,

and he was looking for investors.

Edison squared up for a fight.

Edison was on the back foot.

His direct current system, DC power,

had a very short range, and to make it work he would need Wall Street

to agree to fund the building of hundreds of filthy, coal-burning power stations, all over New York.

Tesla, who had made his name with this, the Tesla Coil,

knew he was on to a winner promoting the alternating current system, AC power.

The advantage of Tesla's system was that it could send electricity hundreds of miles,

which meant all those dirty coal-fired power stations could be

in someone else's back yard.

CHEERING

New York was far too big a prize to lose, and Edison set out to smear AC power.

To demonstrate how dangerous it was, Edison's company began manufacturing...

MAN SCREAMS ..AC-powered electric chairs.

Then, in 1903, Edison's company infamously used AC power to execute Topsy the elephant on Coney Island.

To this day, no-one's certain why, because the battle had been lost and Tesla had already won.

New York's battle of the currents would have far-reaching consequences.

Soon, not just New York

but virtually every city in the world adopted AC power,

precisely because it could be generated in dirty power stations that were built far, far away.

Electricity would have a massive impact on the lives of New Yorkers,

and at the start of the 20th century the city was poised to embrace a new technological age.

But it hadn't quite turned the tide against its 19th-century filth.

And here, on Coney Island, where New Yorkers came to play in the hot summer months,

a stark reminder of the city's dirty past began washing up on the beaches.

Nothing, apart from Jaws, gets Americans out of the water faster than raw excrement.

Ever since the beginnings of New York, New Yorkers had been

pouring their waste into the Hudson and the East River and had been polluting New York Harbour here.

That meant, by the end of the 19th century, Manhattan was an island floating in its own filth.

The city had built a few sewage treatment plants, but they were regularly overwhelmed

by the waste from so many people

and often the sewers would empty straight into New York's rivers.

New York realised it had to build a lot more of these - sewage works.

This is the Newtown Creek Wastewater Treatment Plant,

worth 5 billion.

Its sole job is to remove everything 1.1 million New Yorkers

put down their toilets and drains,

and return clean, treated water back into the East River.

And this is where the filthy raw sewage first comes in.

Whoa, that's raw sewage?

That's raw sewage.

It's actually coming in at a very, very high speed.

I'm nervous to breathe in,

I don't want to get any of those particles in my nose. Wow.

And how much is floating through there now?

Approximately, each one of these channels can manage 110 million gallons a day.

The first step is to filter out the big stuff.

Every day, these rakes pull out over six tonnes

of things the plant can't process -

everything from loo paper and condoms, to mobile phones and cameras.

The material from downstairs is now being raised up.

Oh, man, that's disgusting.

Yeah, that's it. There was a bit of a splash there.

That's New York's best(!)

Raking out the rubbish is the easy part.

Most of this massive 52-acre site is devoted to the next stage -

removing all the really revolting stuff

like urine, blood and excrement from the waste water.

And it's all done using microbiology, air and gravity.

What is in here?

This is where the magic takes place, this is the biological reactor.

This is where the waste water, the microorganisms and the air

come together for a three-hour period.

This amazing process was brought to New York

by sanitary engineer Richard H Gould.

Gould could see the problem facing New York's sewage plants,

centred around the fact that human waste mixed easily with water.

In the late 1920s, he presented his colleagues

with a revolutionary solution from Britain - activated sludge.

Full of the bacteria found in the human gut,

when activated sludge is added to sewage, it begins to eat the waste.

The bacteria take around three weeks to finish the job,

but Gould explained that by adding air,

the process could be shortened to just six hours.

The real magic of the process relied on gravity.

Once the bacteria devoured all the waste,

they became heavier, sinking to the bottom

and allowing the clean water to be easily separated.

Gould revolutionised New York's sewage treatment system.

Today this plant is just one of 14

needed to process the 475 billion gallons of sewage

New York produces every year.

What a fantastic view of Manhattan, but it feels appropriate, right,

because without this place, that place would not exist.

Yeah, that's the iconic styling of Manhattan.

That's where our customers are.

It probably wouldn't be the island it is if it wasn't for the waste water treatment plants.

While the city became ever more reliant on science and technology

to clean up after its human population,

on the streets there remained another major source of excrement...

Horses.

Throughout most of the 19th century, New York's industrial expansion

had relied on horses to move pretty much everything around the city.

Trouble was, they left behind a mountain of manure.

In the late 19th century, there were 200,000 horses

on the streets of New York City.

And every year, they produced over 400,000 tonnes of manure.

Getting rid of all that waste was the holy grail, and as a result,

two fundamentally different types of automobile

were vying with each other to supersede those filthy horses.

Watch out, everyone, coming through.

On one side was the electric car.

The amazing thing is this an electric car, which is the future,

and yet it's 100 years old. This is really going back to the future.

The Detroit Electric, built in 1918, and now worth more than 100,000,

is one of the oldest electric cars still on the road in America.

This is fantastic.

Watch out, dude, I don't want to run you over in my vintage vehicle.

At the end of the 19th century,

there were hundreds of electric cars,

fighting it out with their petrol-engined rivals

to win market dominance on the streets of New York.

Bringing her round.

HORN HONKS

Ooh, urgh, come on.

This is the coolest vehicle I have ever driven in my life.

Electric cars were not only cool,

they produced little noise and no emissions.

But compared to their main competitor,

electric cars had one major drawback.

It was a pretty good car, the trouble was it didn't go that far.

The fate of the electric car was sealed in 1908

when Mr Henry Ford launched this, the famous Model T.

Now, this would have a profound effect on the lives of New Yorkers,

if they could get it started.

It may have taken some effort to get its petrol engine started...

Watch out. Very good, excellent.

ENGINE CHUGS

..but the mass-produced Model T Ford

undercut its cheapest competitor by a third.

Take your foot off the brake.

And one could have been yours to drive away for just 825.

There you go, we're doing good.

It doesn't have power steering, does it? No, no power steering, no.

Woo-hoo! There we go, we're rolling now.

So what effect did this have on cities like New York?

It must have been a revolution.

Yeah, tremendous, tremendous change took place.

Before, these streets that we're driving down right now were filthy,

you know, they had thousands, tens of thousands of horses

and of course, they went to the bathroom all over the streets,

so it was a mess.

I'd say 90% of the horses

were eliminated within about five years of the automobile.

Wow. That's a revolution, isn't it? It is a real revolution.

As mass-produced cars were revolutionising the way

that New Yorkers got around the city,

another revolution of mass production

was taking place in their homes.

And housework would never be the same again.

In the 1920s, door-to-door salesmen started selling this, the Hoover.

The tagline was, "It beats as it sweeps as it cleans."

Round about the same time, Edison's General Electric Company launched this,

the world's first mass-produced consumer refrigerator,

with the tagline, "Makes it safe to be hungry."

Like every great marketing campaign, this one had a memorable jingle.

JAUNTY PIANO

# It's here, it's there, it's everywhere...

In the 1920s, fridges and cars became potent symbols

of a new, clean, technologically-driven American dream.

New York was swept by a tidal wave of consumerism,

as mass production made them ever more affordable for everybody.

But it soon became apparent this progress came at a price.

Not only were the streets soon jammed with cars,

there was another drawback to driving a Model T in New York traffic.

A big problem with these early motor cars

is the engines kept stuttering - or pinking, as they called it.

It was because the petrol was actually burning too well in the engine.

So in 1920, the chemical engineer Thomas Midgley Jnr

set out to try and find an alternative.

Midgley needed to find a way to make petrol less flammable.

So he began working his way through the elements

to see which one would do the job.

Eventually, he hit upon the solution.

And here it is...

lead.

He'd only gone and just invented leaded petrol.

Realising deadly lead might be a bit of a hard sell,

Midgley launched his new additive under the name of ethyl

and took big whiffs of it to prove it was safe.

MAN VOMITS

Not long after, Midgley ended up with lead poisoning,

and had to spend a year in Florida recovering.

It turned out that lead doesn't actually burn in a car's engine,

it comes straight out of the exhaust, polluting the atmosphere.

Yet amazingly, even though there were soon unleaded alternatives...

..because the oil companies owned the patent,

leaded became the standard for most of the 20th century,

and it wasn't banned in New York until 1996.

Midgley had done his bit to ensure

that the smog that would come to plague the 20th century

would be that little bit more noxious. But he wasn't finished yet.

Next, this genius turned his attention to fridges.

Midgley knew there was a very obvious problem with early fridges.

The gas used to make them cool would sometimes catch fire

and occasionally...

..explode.

A bit of a problem.

So Midgley set about searching for a gas that didn't.

He came up with another brilliant idea, Freon,

the world's first chlorofluorocarbon - otherwise known as a CFC.

Midgley didn't realise it,

but he'd invented a gas that would decimate the world's ozone layer.

In the space of ten years, Thomas Midgley had managed to create

two of the most environmentally deadly pollutants in history,

leaded petrol and CFCs.

And with New York's growing appetite for fridges and cars,

the world's largest city was set to become one of its biggest pollutants.

New York's population, wealth, traffic,

power consumption and its pollution

would all continue to rise throughout the 20th century.

Only now are we coming to terms with the vast amounts of unseen filth

our modern cities create.

Many of the technological solutions

that transformed New York City in the 19th century

produced waste that has blighted the 21st.

Every 15 minutes, New York produces enough greenhouse gases

to fill the entire Empire State Building.

That's 58 million tonnes a year, or seven tonnes per person per year.

And of course, those gases cannot be confined

to the city that created them. Now it's a truly global problem.

Our cities have always teetered on the edge of being destroyed by their own filth.

Through the centuries,

we've developed more sophisticated ways of dealing with waste.

Our battle against our filth has given us laws, governments and inventions

that have allowed millions of us to live together in vast cities,

of which New York is the ultimate example.

But that struggle is far from over.

This glamorous city with its glittering skyline

would drown in its own sewage and rubbish in a matter of days

if its complex waste-disposal mechanisms broke down.

Our battle against our filth will never be over.

Subtitles by Red Bee Media

E-mail subtitling@bbc.co.uk