18thcentury 19thcentury africanamericans andprotectingsuchofthemashavebeen antislaverymovements civilrights freeafricanamericans history historynew-yorksocietyforpromotingthemanumissionofslaves historypennsylvaniasocietyforpromotingtheabolitionofslavery middleatlanticstates ormaybeliberated pennsylvaniasocietyforpromotingtheabolitionofslavery politicalactivity racerelations