The viaduct opened on January 29, 1893, and originally led to Reading Terminal in Center City Philadelphia.

[1] The viaduct heads north from Reading Terminal and at Callowhill Junction, forks, with the Ninth Street Branch formally merging with the current SEPTA Main Line.

The viaduct cuts through the street grid at a diagonal angle, creating several irregularly shaped lots.

[7] The southern section of the viaduct, south of Vine Street, was razed in 1990 to make way for the Pennsylvania Convention Center.

[3][9] This effort was led by two local artists, John Struble and Sarah McEneaney,[4][11] who in 2004 formed a nonprofit called Friends of the Rail Park.

[8] Students at the University of Pennsylvania School of Design suggested converting the viaduct into a rail trail similar to the Promenade Plantee in Paris.

[4] The success of New York City's High Line, a similar rail trail which opened in 2009, encouraged further efforts to convert the Reading Viaduct to a park.

[3][5][11] Although gates had been installed to prevent access to the decrepit viaduct, people still trespassed anyway, leaving debris and garbage there.

In addition, Reading International owed $1.4 million in unpaid taxes and was required to conduct environmental remediation.

[8] However, residents of the nearby Chinatown neighborhood preferred demolishing the viaduct, as they feared that it would lead to gentrification.

[10][25] The commonwealth of Pennsylvania provided a $3.5 million grant in September 2016, which covered all remaining funding shortfalls.

[33] Supporters of the Rail Park were raising $60 million for the second phase, including environmental work and land acquisition.

[34] This was complicated by the fact that the route had never been formally abandoned; this meant that the viaduct could theoretically be reopened for rail service at any time, even though it had been partially demolished.

[35] Work on the second phase stalled for several years,[8] and the abandoned Ninth Street Branch portion was used as an illegal dumping ground.

[8][36] By 2024, Reading International wanted to sell the unused part of the viaduct for $50 million, a figure the Philadelphia government was unwilling to pay.