"How is it that we hear the loudest yelps for liberty among the drivers of negroes?"--Samuel Johnson, 1775.
But mark you, in the original Declaration of Independence Thomas Jefferson had put in an anti-slavery clause, that was removed at the insistence of South Carolina and Georgia; their support was deemed essential. Samuel Adams said to Ben Franklin, "Mark me, Franklin, if we give in on this issue, there will be trouble a hundred years hence; posterity will never forgive us." In slightly less that those hundred years, we had the Civil War.