King Charles II granted William Penn a royal charter for a 26-million-acre (110,000 km2) tract of land – west of New Jersey and north of Maryland – on which to develop an English colony.

He arrived with his surviving daughter Letitia (1678–1745), and his second wife, Hannah Callowhill (1671–1726), who gave birth to their son John (1700–1746) in the colony.

In his Annals of Philadelphia (1830), antiquarian John Fanning Watson argued that the two-and-a-half-story brick house at Letitia Street and Black Horse Alley had been William Penn's city residence during his 1682-84 visit.

But despite that building's direct associations with the Penn family and Pennsylvania's colonial government, and despite desperate calls by antiquarians to preserve it, the Slate Roof House was demolished in 1867.

The Bi-Centennial Association of Pennsylvania was formed to raise funds through subscription to relocate the house, and to organize a week-long anniversary celebration for October 1882.

[12] The parades, historical pageants, athletic events (including a regatta on the Schuylkill River), concerts and fireworks went on as scheduled.

"[d] PMA took on administration of the house, operating it as a small museum exhibiting Queen Anne style furniture and decorative arts objects.

[19] After a period of vacancy, in 2017, the Centennial Parkside Community Development Corporation leased the house and renovated the interior with support from the William Penn Foundation.