The High Line is a 1.45-mile-long (22 blocks) abandoned elevated railway, that stretches from the Hudson Rail Yard at 34th Street down through the West Chelsea gallery neighborhood where it continues on to Gansevoort Street in the Meatpacking district. It has recently been developed into one of New York City's more remarkable public parks. Opened to the public in June 2009, just a few years ago the High Line's demolition seemed imminent. But Mayor Michael Bloomberg said that the High Line's restoration is at the "core of the administration's plans to revitalize the Far West Side," forming "a necklace of dynamic waterfront communities, each with their own assets."

The High Line reveals a lot about New York City history. The following history is from Friends of the Highline, an activist group founded by Joshua David and Robert Hammond to advocate for the High Line's preservation and reuse as public open space:

Before the High Line In 1847, the City of New York authorized the street-level railroad tracks running down Manhattan's West Side as far south as Canal Street to allow freight to run between New York City and Albany.

Days of Death Avenue As soon as traffic started running on the new line, accidents began occurring between trains, pedestrians, horses, and other traffic. So many fatalities occurred that 10th Avenue became known as "Death Avenue". Men on horses had to ride in front of trains waving flags. They were called the West Side Cowboys.

The West Side Improvement Project After years of public debate about these hazardous conditions and how to eliminate them, the New York Central Railroad, the City of New York, and the State of New York, came to an agreement in 1929 for the West Side Improvement Project, which included the High Line. This project as a whole was 13 miles long, eliminated 105 street-level railroad crossings, and added 32 acres to Riverside Park. It cost over $150 million in 1930 dollars—more than $2 billion in today's dollars.

The High Line ran from 35th Street down to St. John's Park Terminal, which covered four riverfront blocks between Clarkson and Spring Streets. The structure was designed to go through the center of blocks, rather than over the avenue, to avoid creating the negative conditions associated with elevated subways. It connected directly to factories and warehouses, allowing trains to roll right inside the buildings. Milk, meat, produce, and raw and manufactured goods could come and go without causing any street-level traffic.

Decline of Rail Traffic and Partial Demolition In the 1950s, the rise of interstate trucking led to a decline of rail traffic on the High Line. Parts of it were torn down in the 1960s, and trains stopped running on it in 1980, when the northern end of the structure and its easement were rerouted to accommodate construction of the Jacob Javits Convention Center. At the southern end, a five-block section of the Line was torn down in 1991, bringing the Line's southern terminus to Gansevoort Street.

The Threat of Demolition Since the mid 1980s, a group of private property owners who purchased land under the High Line at prices that reflected its easement have lobbied for demolition of the entire structure. Much credit for the fact that the High Line survived the demolition efforts in the mid- and late 1980s goes to Peter Obletz, a Chelsea resident, activist, and railroad enthusiast, who challenged demolition efforts in court and tried to reestablish rail service on the Line.

The High Line Festival In May 2007 the first annual High Line Festival took place, featuring curator and co-founder David Bowie headlining this ten-day program of movies, music, visual arts, dance, and the customary over-the-top Chelsea nightlife.