He directly aided fugitive slaves and also kept records of the people served in order to help families reunite.

First, his father had bought his freedom in 1798 from his master in Caroline County, Maryland, on the Eastern Shore and moved north to New Jersey.

Peter, his wife "Vina", and most of his family escaped from slavery when he was about age 50, with the help of two brothers named Friedman, who operated mercantile establishments in Florence, Alabama, and Cincinnati, Ohio.

[7][8] Later Peter Still sought help at the Pennsylvania Anti-Slavery Society, seeking to find his parents or other members of his birth family.

[6] William's other siblings included Levin, Jr.; Peter; James; Samuel; Mary, a teacher and missionary in the African Methodist Episcopal Church; Mahala (who married Gabriel Thompson); and Kitturah, who moved to Pennsylvania.

In 1847, the same year he was hired as a clerk for the Pennsylvania Society for the Abolition of Slavery, Still married Letitia George.

After he died, she married again, to the Reverend Matthew Anderson, longtime pastor of the Berean Presbyterian Church in North Philadelphia.

Robert George Still (1861–1896) became a journalist and owned a print shop on Pine at 11th Street in central Philadelphia.

[11] When Philadelphia abolitionists organized a Vigilance Committee to directly aid escaped slaves who had reached the city, Still became its chairman.

In 1855, he participated in the nationally covered rescue of Jane Johnson, a slave who sought help from the Society in gaining freedom while passing through Philadelphia with her master John Hill Wheeler, newly appointed US Minister to Nicaragua.

Still and others liberated her and her two sons under Pennsylvania law, which held that slaves brought to the free state voluntarily by a slaveholder could choose freedom.

Jane Johnson returned to Philadelphia from New York and testified in court as to her independence in choosing freedom, winning an acquittal for Still and four others, and reduced sentences for the last two men.

[11] In 1859, Still challenged the segregation of the city's public transit system, which had separate seating for whites and blacks.

Still worked with other Underground Railroad agents operating in the South, including in Virginia ports, nearby Delaware and Maryland, and in many counties in southern Pennsylvania.

William Still provided material support and encouragement for Harriet Tubman to begin her work as a conductor of the Underground Railroad.

[18][19] In 1867, Still published A Brief Narrative of the Struggle for the Rights of Colored People of Philadelphia in the City Railway Cars.

[12][21] Historians have since used it to understand how the Underground Railroad worked; both Project Gutenberg[22] and the Internet archive[23] make the text freely available.

After the war, Still continued as an active businessman, philanthropist and social activist in the Philadelphia metropolitan areas.

[24] He was a member of the Freedmen's Aid Union and Commission, an officer of the Philadelphia Home for the Aged and Infirm Colored Persons, and an elder in the Presbyterian church (where he established Sabbath Schools to promote literacy including among freed blacks).

[34] This also affirmed Still's national importance as a leading Underground Railroad agent in a major center of abolition.