Links?
http://www.pbs.org/benfranklin/l3_citizen_abolitionist.html
on Franklin
http://www.factcheck.org/2007/12/presidents-who-owned-slaves/
Grant owned a slave named William Jones, whom he freed in 1859.
Slavery was legal in every U.S. Colony prior to the revolution. A vast majority of the signers of the Declaration of Independance and the Constitution where slave holders.