[2][3] The founder, Free Frank McWorter (1777–1854), was a former slave who was able to save money from work and his own business to purchase the freedom of his wife, then himself, and over time, 13 members of his family from Kentucky.

[2] The town was integrated, with blacks and whites involved together in community organizations, except only a typical 19th-century segregated cemetery.

However, by the late 20th century, all vestiges of New Philadelphia had vanished save fragments of glass and pottery, and traces of the town's gravel streets.

[12][13] The town site was added to the U.S. National Register of Historic Places on August 11, 2005;[1] In 2008, Christopher C. Fennell of the University of Illinois at Urbana-Champaign led the summer excavation team under a new grant.

[14][15] In June 2008, the Public Broadcasting Service filmed material at the dig, which was released as an episode of Time Team America.

[16] On January 16, 2009 the Department of the Interior designated the New Philadelphia Town Site a National Historic Landmark based on the significance of its history and archaeology.

[18] A preliminary study conducted by the National Park Service in 2012 found that New Philadelphia had significant archaeological and historical value, but because the sites' remains are buried underground, challenges in providing for public enjoyment and other issues would make it unsuitable as a unit of the National Park System.

[19] Despite the NPS's recommendation against a full special resource study, the Carl Levin and Howard P. "Buck" McKeon National Defense Authorization Act for Fiscal Year 2015 incorporated a bill from Representative Darin LaHood directing the Department of Interior to study the New Philadelphia townsite for possible NPS designation.

[20][21][8] Although the special resource study had not yet been completed,[22] legislation was included in the Consolidated Appropriations Act, 2023 to establish New Philadelphia National Historic Site, consisting of 124.33 acres.