“Every slave is a stolen man; every slaveholder is a man-stealer.”
By no precedent, no example, no law, no compact, no purchase, no bequest, no inheritance, no combination of circumstances, is slaveholding right or justifiable. While a slave remains in his fetters, the land must have no rest.
“No Compromise with the Evil of Slavery” (1854) essay http://etc.usf.edu/lit2go/185/civil-rights-and-conflict-in-the-united-states-selected-speeches/5061/no-compromise-with-the-evil-of-slavery-speech-1854/