Behind the Marker
Purvis was one of the original leaders of the Philadelphia Vigilance Committee, which helped to organize the city's Underground Railroad activities. He was also a founding member of the American Anti-Slavery Society and president of the Pennsylvania chapter.

Although he appeared to many to be white, Purvis considered himself African American. His maternal grandmother was an African-born slave. His maternal grandfather was a German-Jewish immigrant. His mother was born in South Carolina and married a wealthy white English businessman. His parents moved to Philadelphia, where Purvis was born and raised. He graduated from Amherst College, and married the daughter of noted Philadelphia black businessman James Forten.

Before the Civil War, the building where Purvis hid escaped slaves was located at Ninth and Lombard Streets, but it was not his primary residence. Purvis lived with his family at a farm in Byberry, Bucks County, because local white mobs, believing that he was a white man married to a black woman, kept targeting his city home for vandalism. The racism of his neighbors enraged Purvis, who wrote that "the apathy and inhumanity of the Whole community" demonstrated the "utter and complete nothingness" of blacks in nineteenth-century American society.