The abandoned spur has been redesigned as a "living system" drawing from multiple disciplines which include landscape architecture, urban design, and ecology.

The High Line was inspired by the 4.7 km (2.9 mi) long Coulée verte (tree-lined walkway), another elevated park in Paris completed in 1993.

Originating in the Meatpacking District, the park runs from Gansevoort Street—three blocks below 14th Street—through Chelsea to the northern edge of the West Side Yard on 34th Street near the Javits Center.

A nonprofit organization called Friends of the High Line was formed in 1999 by Joshua David and Robert Hammond, advocating its preservation and reuse as public open space, an elevated park or greenway.

The Spur, an extension of the High Line that originally connected with the Morgan General Mail Facility at Tenth Avenue and 30th Street, opened in 2019.

The park became a tourist attraction and spurred real estate development in adjacent neighborhoods, increasing real-estate values and prices along the route.

[18][19] The Tenth Avenue Spur is composed of three parts: the Coach Passage, with 60-foot-tall (18 m) ceilings; the High Line's largest planted garden; and a plaza with temporary art exhibitions that get replaced every 18 months.

Creative Time, Friends of the High Line, and the New York City Department of Parks and Recreation commissioned The River That Flows Both Ways by Spencer Finch as the inaugural art installation.

Creative Time worked with Finch to realize his site-specific concept after he saw the rusted, disused mullions of the old factory, with metal-and-glass specialists Jaroff Design helping to prepare and reinstall.

[47][48] Also installed during the second phase of construction was Julianne Swartz's Digital Empathy, a work utilizing audio messages at restrooms, elevators, and water fountains.

[56][57] For safety the railroad hired "West Side cowboys", men who rode horses and waved flags in front of the trains.

[62] The 13-mile (21 km) project eliminated 105 street-level railroad crossings, added 32 acres (13 ha) to Riverside Park, and included construction of the West Side Elevated Highway.

[60][55] The growth of interstate trucking during the 1950s led to a drop in rail traffic throughout the U.S.[68] St. John's Freight Terminal was abandoned in 1960,[73] and the southernmost section of the line was demolished in the following decade due to low use.

Peter Obletz, a Chelsea resident, activist, and railroad enthusiast, challenged the demolition efforts in court and tried to re-establish rail service on the line.

[58][75][77] Obletz offered to buy the viaduct for $10 in order to run a small amount of freight trains on the line, and Conrail accepted, mainly because demolition would have cost $5 million.

Around this time, it became known to urban explorers and local residents for the tough, drought-tolerant wild grasses, shrubs (such as sumac) and rugged trees which had sprung up in the gravel along the abandoned railway.

[60][80] The Interstate Commerce Commission approved plans to demolish the structure in 1992, but demolition was delayed due to disputes between various city government agencies and the railroad companies.

[85] The organization was initially a small community group advocating the High Line's preservation and transformation when the structure was threatened with demolition during Rudy Giuliani's second term as mayor.

[87] Mary Boone's art gallery, as well as Martha Stewart and Edward Norton, hosted fundraising benefits for the High Line in 2001 and 2002 respectively.

[81] Fashion designer Diane von Fürstenberg (who had moved her New York City headquarters to the Meatpacking District in 1997) and her husband, Barry Diller, also organized fundraising events in her studio.

[74][89] In July 2003, Edward Norton and Robert Caro hosted a benefit event at Grand Central Terminal, where the submissions for the design contest were exhibited.

[81] The same month, a bipartisan group of city officials began petitioning the federal Surface Transportation Board to hand over title to the viaduct for park use.

[92] The Surface Transportation Board issued a certificate of interim trail use on June 13, 2005, allowing the city to remove most of the line from the national rail system.

[126] On January 11, 2021, Governor Andrew Cuomo announced proposals to extend the High Line east to Moynihan Train Hall and north to Hudson River Park.

[137] Friends of the High Line has been run by president and co-founder Josh David after executive director Jenny Gersten stepped down in 2014.

[10] The recycling of the rail line into an urban park and tourist attraction has revitalized Chelsea, which was "gritty" and in generally poor condition during the late twentieth century.

Park advocates attributed this to the visibility of the High Line from surrounding buildings, a feature of urban life espoused by author Jane Jacobs nearly fifty years before.

"[154] In a review of the Highliner restaurant—which has now reverted to its previous name, the Empire Diner—Ariel Levy wrote in The New Yorker that... "The new Chelsea that is emerging on weekends as visitors flood the elevated park ... [is] touristy, overpriced, and shiny.

[156] Several cities nationwide have plans to renovate railroad infrastructure into parkland,[157] including Philadelphia's Rail Park, Atlanta's Belt Line, and Chicago's Bloomingdale Trail.

[175] Other works with scenes on the High Line since its conversion include The Simpsons 2012 episode "Moonshine River"[176], the 2012 film, What Maisie Knew[177], and the 2022 book by Adam Silvera, The First to Die at the End.