18thcentury 19thcentury africanamericans americancolonizationsociety andprotectingsuchofthemashavebeen antislaverymovements civilrights colonialperiod(1600-1775) emancipation freeafricanamericans history historynew-yorksocietyforpromotingthemanumissionofslaves historypennsylvaniasocietyforpromotingtheabolitionofslavery middleatlanticstates new-yorksocietyforpromotingthemanumissionofslaves ormaybeliberated pennsylvaniaanti-slaverysociety pennsylvaniacolonizationsociety politicalactivity racerelations sklaverei slavery slaves socialscience unitedstates