It was installed in 1839 to mark the completion of the Newkirk Viaduct, the first permanent railroad bridge over the Schuylkill River.

Designed by Thomas Ustick Walter, a future Architect of the Capitol, the monument was erected by the Philadelphia, Wilmington and Baltimore Railroad to mark its completion of a bridge across the Schuylkill River and the first railroad line south from Philadelphia.

Between 1927 and 1930, it was moved about 600 feet (180 m) further inland, where it sat for decades by the main line that became Amtrak's Northeast Corridor.

The monument commemorates the 1838 completion of the Newkirk Viaduct, also called the Gray's Ferry Bridge, over the Schuylkill River.

The bridge completed the first direct rail line between Philadelphia and Baltimore, Maryland — tracks that closely paralleled the King's Highway, the main land route to the southern states.

On August 14, 1838, the PW&B board of directors decided to name the bridge after company president Matthew Newkirk (1794–1868), a Philadelphia business and civic leader, and to commission a monument at its west end.

(Earlier in the year, the company gave Newkirk a silver plate worth $1,000 ($28,613 today[3]) to reward him for arranging the merger of four railroads that together built the Philadelphia-Baltimore line.

[2] The obelisk and base are inscribed with the names of 51 men,[6] including senior officials of the four railroads and various employees who helped build the bridge and rail line.

It leased its old line to the Philadelphia and Reading Railway, which built a small railyard, surrounding the monument.

"Surrounding the structure is an iron fence to protect it from vandalism, but it has, nevertheless, been a frequent target for irresponsible hoodlums," the Philadelphia Inquirer wrote in 1896.

"[12] By January 1926, the Pennsylvania Railroad was making plans to move the monument "because of the additional yard facilities which are required at that point.

[10][1][14] It was moved sometime between May 1927, when an aerial photo shows it still in its original location,[15] and September 1930, when the Philadelphia Inquirer ran a letter describing the monument in its new site.

[16] (In 1939, a retired Pennsylvania Railroad employee—perhaps having forgotten the actual year of the move—told the Delaware County Daily Times that the monument had been moved in late 1917 to make way for the "Hog Island Railroad"—formally, the 60th Street Branch of the Pennsylvania Railroad—and that three of Newkirk's daughters had been asked their permission for the move.

[8] In 2013, interest in the Newkirk Monument was rekindled by a pair of articles[1][18] written by Bradley Peniston for Hidden City Philadelphia, a local organization concerned with the built environment.

Over the next few years, the idea was embraced and brought to fruition by a host of public and private entities, including Amtrak, Philadelphia Parks & Recreation, Schuylkill River Development Corporation, landscape architects Andropogon Associates, planners PennPraxis, conservators Materials Conservation, and movers with the George Young Company.

On November 17–18, 2016, the monument was moved to a new concrete pad along the under-construction "Bartram's Mile" section of the Schuylkill River Trail.

J.J. Cohen Jr. Wilmington, David C. Wilson, James Price, William Chandler, Edward Tatnell,[24] Joseph C. Gilpin, Mahlon Betts, Henry Whitely, Jas.

Railroad Contractors: William Slater, John Ahern, Beers & Hyde, Kennedy Lonergan Superintendents:

Wilson's transcription contains several errors; for example, it misspells the last names of Henry Hazlehurst, Edward Tatnall,[18] and Charles and Alexander Provest.