In the late 1800s, New York City streets were covered with millions of pounds of horse manure thanks to a widespread horse-driven transportation industry.

New York City's carriage horses are a holdover from a time when the city was home to hundreds of thousands of horses roaming its streets.

Before modern sanitation, New York City let pigs roam the streets to eat its garbage

In the early 1820s, an estimated 20,000 hogs roamed Manhattan's streets, feeding on trash that the city lacked a system to collect. Pigs were eventually banned at the urging of wealthy residents, who feared they would deter tourists and drive down property values.

The sewage of New York City

Residents of the five boroughs of New York produce 1.3 billion gallons of wastewater everyday. Seventy miles of sewer pipes, first built in the mid-1800s, feed the sewage to 14 wastewater treatment and recovery plants where the waste is treated back to viable, drinkable water. See what shouldn't go down the toilet here.

Mass transit in America began with horse-drawn omnibuses in New York City in 1827

The omnibus, a large horse-drawn stagecoach that ran a fixed route and carried a dozen riders at an affordable fare, was different from a private carriage because it carried everyone, not just the wealthy.

New York City spends $429 million a year just to get rid of its trash

None of NYC's garbage is processed within the city. It is transported by truck, train, and barge to waste-to-energy facilities and landfills as far away as Ohio and South Carolina, a vast logistical operation.

Boston opened the first subway tunnel in the US in 1897

By the end of the 19th century, nearly 400,000 people were packed into less than a square mile of downtown Boston, with 8,000 horses pulling trolleys through streets choked with noise, manure, and congestion. This prompted the city to pursue a then-controversial subway system.

Essential pipes, sewers, and cables lie buried beneath New York City

The Department of Design and Construction offers a tour of its work sites, explaining the complex systems that exist underground. Gas, electrical, telecom pipes, and many others, sprawl out underneath the entire city, with dozens of maps that help workers know where they're placed. This layout is unusual compared to the rest of the country, where wires are often present and visible above ground.

Read a complete history of urban mass transit in the United States

Explore the rise and fall of American mass transit, from the horse-drawn omnibus era through the streetcar age to the automobile's dominance. In the 1920s, streetcars carried 12 to 13 billion riders per year. By 1963, that number had shrunken to 300,000.

In the 1930s, New York banned buskers as part of an antinoise campaign

Mayor Fiorello LaGuardia was hoping to modernize the city and believed that street performers only crowded the streets and added to an annoying cacophony. Residents wrote to the mayor to protest the decision, arguing that buskers were appreciated by the public.

As graffiti grew more popular, New York worked to stop it

In 1972, the NYPD made over 1,500 graffiti-related arrests. By 1973, the city was annually spending $10M to remove and limit graffiti. That same year, a poll conducted by an anti-graffiti task force found that the "vast majority" of residents did not consider graffiti to be art.

In 1711, the New York City Common Council decided that the city’s slave market would operate on Wall Street

In 1711, the New York City Common Council decided that the city’s slave market would operate on Wall Street. Back then, the nation’s economy rode on the backs of slave labor and the slave trade itself—meaning that the slave market’s location was an economic hub for the city.

The complex science of snow removal

Plowing snow seems simple, but its actually a technically complex task and requires significant logistics, patience, and funding. New York City's 19,000 miles of roads require days to plow at a cost of $12M per inch of fallen snow, and roughly 17 million tons of salt were applied to road surfaces across the US in a recent year. Dive into the details of snow removal with an in-depth and funny video.

Infrastructure projects in New York are much more difficult today

The Erie Canal was one of the most ambitious infrastructure projects in American history. Many have said such an effort would be impossible today. This article explores why that is the case and ponders the future of large-scale American infrastructure development.

The Erie Canal transformed New York City into America’s banking capital

By redirecting western trade through New York Harbor, the canal turned New York into the nation’s commercial hub. This surge in commerce shifted financial power from Philadelphia to Wall Street, establishing the city as America’s banking capital.

NYC's first subway was built largely in secret

In 1870, Alfred Ely Beach secretly tunneled under Broadway in 58 nights, disguising his pneumatic subway as a mail tube to fool Tammany Hall, the corrupt political machine that ran New York City. Nearly half a million New Yorkers rode it before politics, and a stock market crash killed the project.

1970s New York was viewed by many as a city in decline

By 1975, the city owed $5B to $6B in short-term debt; over a million manufacturing jobs had left the city since the end of World War II. Meanwhile, the murder rate was more than double than 10 years earlier. Graffiti was seen as illegal vandalism perpetrated by unsupervised teenagers and was viewed by some as emblematic of the larger societal decline.

See how New York City has grown since 1609

Wall Street and the southern tip of Manhattan were the first parts of the island to be developed beyond farmland by Dutch and English settlers. It wasn’t long until New York City resembled the city we know today.

How a polluted New York City waterway created extremophiles hungry for 'black mayonnaise'

In the 19th century, coal processing plants, oil refineries, a tannery, and other industries lining the Gowanus Canal contaminated its waters with coal tar, sewage, and other pollutants, forming the toxic sludge. Samples taken from the site before clean-up efforts revealed over 450 species of microbes with metabolisms adapted to break down these contaminants.

August A. Busch, Sr. was gifted a six-horse Clydesdale hitch to celebrate Prohibition’s end

This helped reveal the marketing power of a horse-drawn beer wagon, so it invested in a second six-horse Clydesdale hitch. The Clydesdales soon went to New York, where they drew a crowd of thousands en route to the Empire State Building. Anheuser-Busch even gifted a case of Budweiser to New York Governor Alfred E. Smith in thanks for his help in the fight against Prohibition.

Paris and Boston were redesigned partly to combat cholera's spread

Georges-Eugène "Baron" Haussmann, who oversaw Paris's redesign in the 1800s, replaced many of the city's narrow streets with wide boulevards. This was done at least in part to bring more air and light into the city to help control cholera. Architect Arthur Gilman redeveloped Boston's Back Bay to similarly combat cholera, among other reasons.

Watch a visualization of New York City's greenhouse gas emissions

About 1.72 tons of carbon dioxide-equivalent gases are released into the atmosphere every second in the Big Apple, enough to fill a balloon 33 feet across at standard pressure and 59 degrees Fahrenheit. After a day, the spheres would pile up into a pyramid whose base spans from the bottom of Manhattan to the south of Central Park.

Visualizing New York City's public transportation commutes

New York City is one of the largest cities in the world, and transports one of the largest numbers of commuters on a daily basis. This data visualization tells the stories of those commuters, showing the varying volume of travelers throughout the week and day, where they are going, and maps of high-traffic areas like stadiums and midtown. Dive into the data here.

The canal carried germs as well as goods

In 1832, North America’s first cholera epidemic spread inland by way of the Erie Canal, carried by immigrants arriving on ships. Fearful towns barred passengers from disembarking, yet cholera, smallpox, and other diseases still traveled the waterway.

The evolution of New York City

Originally founded as New Amsterdam, this interactive timeline lists out and provides deep dives on the major events that shaped New York City as it became America's foremost cultural and economic hub.

Horse diving was a popular attraction for 50 years

The event, which took place in Atlantic City, is exactly as it sounds: horses, directed by (sometimes scantily clad) riders, would jump from diving boards into pools. Although it was a popular spectacle for decades, it fell out of favor by the late 1970s.

An overview of New York's iconic stoops

In New York City, stoops are cherished and fundamental aspect of life in many neighborhoods. In a city where yards are a rarity, stairways are places for New Yorkers to socialize and relax. Follow the history of these sites in this video, starting from their Dutch origins to their impact on city life today.

DeWitt Clinton’s “Big Ditch” gamble transformed New York

Mocked as “Clinton’s Folly” and “Clinton’s Big Ditch,” New York Gov. DeWitt Clinton championed the Erie Canal against skeptics. His political drive secured funding for the project in 1817.

Mapping early New York

Want to see how Wall Street (and New York City as a whole) has changed over time? Use this timeline and map to see Manhattan today overlaid with the precise boundaries of early land grants to the Dutch in the 1600s. Scroll through the progress of city building through the first century of European settlement there.

Travel the 363-mile Erie Canal, the waterway that cut freight costs by 90% and opened the American frontier.

The history of Wall Street as a financial center dates back to the 1700s, beginning with the establishment of the New York Stock Exchange and New York City's first official slave market.

Niagara power helped electrify early New York City

Tesla's AC system at Niagara Falls was so successful that electricity generated there lit up Broadway theaters and powered NYC's subway system in the early 1900s.

John Snow—not the one from 'Game of Thrones'—determined that contaminated water sickened London

His pioneering epidemiology work during an 1854 cholera outbreak mapped out the commonalities between people in London who were getting sick. He discovered that ill people were getting water from the same Broad Street pump. Before Snow's work, the prevailing theory was that bad air sickened individuals instead of cholera-causing bacteria in the water.

How US horse breeders sourced animals from the Syrian desert

Alexander Keene Richards was a pioneer in thoroughbred racing in the US in the 1800s, a time when every town with a few thousand people had a horse track. This interview highlights how Richards went to great lengths to perfect horse breeding.

The New York Stock Exchange wouldn't have been made if not for municipal bond sales

The Funding Act of 1790 nationalized and consolidated the debt held by the 13 colonies to be sold off in the form of bonds.

New York was once called New Amsterdam

Although New York has a long history, it wasn’t actually called “New York” until the late 1600s, when the English beat out the Dutch for control of the area. In 1664, Dutch Governor Peter Stuyvesant surrendered what used to be known as “New Amsterdam” to the English, who renamed it New York after the Duke of York.

How LA brought water to its booming population

By the turn of the 20th century, Los Angeles had grown from a dusty, crime-ridden pueblo into a thriving metropolis. The only problem was that it was growing too fast. Here's the story of how the booming town created a massive water infrastructure to redirect area rivers to its residents.

Erie Canal builders invented the “stump puller” to clear forests

One ingenious device created for the Erie Canal was the stump puller—a horse-powered machine using levers and chains to rip tree stumps from the ground.

An anthropologist spent years riding garbage trucks to understand what our trash says about us

Robin Nagle rode with New York City sanitation workers to trace the hidden life of what we throw out. Her research explores what the things we discard reveal about who we are. 1440 explores the hidden life of trash.