Horrendous traffic problems plagued New York City in the 1860s, particularly as its residential area expanded outwards. Streetcars–first pulled by horses, then by steam engines, and then by cables-- had been in operation in Manhattan since the 1830s, but were generally slow, inefficient, dangerous to pedestrians, and did little to alleviate traffic congestion. By the mid-1860s, a method was needed for moving large numbers of people up and down Manhattan's narrow length without adding to the gridlock.

London also suffered from traffic congestion. By the early 1860s, gridlock had become such a problem that the city's economy began to suffer. Beginning in 1863, the Metropolitan Railway Company dug up four miles of streets in central London, laid tracks in the trenches, built a brick-lined tunnel to house the rails, and recovered the surface. With this, the world's first underground railway was born.

Inspired by London's project, New York City entertained several proposals for an underground railway of its own. The potential cost of such a project was extremely high. Building a successful subterranean transportation system for New York City required the development of new technologies that would allow a network of rails to be laid under bustling sections of the city without thoroughly disrupting city life, as had happened in London when the streets were dug up. New York City was hardly on firm fiscal ground in the late-1860s and early-1870s, as Boss Tweed's ring of corrupt politicians defrauded the city out of millions of dollars, much of it under the guise of public works projects. Private companies were, for the most part, unwilling to take the risk themselves of developing the technology needed for subterranean travel when the promise of a return on their investment was uncertain at best.

This image depicts Alfred Beach's plan for a pneumatic subway in lower Manhattan. The plan was to construct a gigantic blowing engine that would force air into a tunnel and move the car along. Image from Scientific American, March 5, 1870

One company, however, did experiment. Alfred Ely Beach's Pneumatic Transit Company secretly built a one hundred-meter pneumatic subway under Broadway near City Hall in 1870, and then demonstrated it to the public with great fanfare. Beach had a less than amicable relationship with Tammany Hall, however, and entered a protracted battle with Boss Tweed over funds to extend his project just as Harper's Weekly cartoonist Thomas Nast was exposing the corruption of the Tweed ring. Following the fallout from Tweed's indictment, public enthusiasm for Beach's project waned, and he was unable to raise sufficient capital to complete the city's first subway.

Rather than attempting fund the development of the technology for building below ground in the 1860s, other entrepreneurial New Yorkers decided in the 1860s to build above ground–well above ground. Charles Harvey organized the West Side and Yonkers Patent Railway Company in the late 1860s and built the city's and the nation's first elevated railway, which ran between Dey and 29th Streets along Greenwich Street and Ninth Avenue. Tracks were built on top of massive iron and steel structures that rose thirty feet off of the ground. Initially, wooden cars were pulled by cable from station to station; but soon steam engines replaced the unreliable cables. Although Harvey's company ultimately failed, it was soon reconstituted as the New York Elevated Railway Company. The elevated line was extended to the north and to the south; by 1878 it ran along Ninth Avenue from South Ferry all the way to 61st Street.

The success of the Ninth Avenue elevated line spawned other lines built by other companies, and by 1880 els stretched up Manhattan along Second, Third, and Sixth avenues from the southern tip of the city to 155th Street, with connections to the depots of railroads to outlying burghs in Westchester and on Long Island. While the "els" did much to ease congestion on city streets, they caused other problems, especially increasing the city's already substantial air pollution. The trains spewed ashes, sparks, and soot on the streets and buildings below them and were extremely noisy. Nevertheless, els became a central component in the cityscape in the decades after the 1880s. By 1888, an estimated 50,000 people depended on the els to move them between home and work each day.