The only F. F. I can think of who actually had a change of heart and freed his slaves at the end of the Revolutionary War was Ben Franklin. He had owned slaves himself, but began to doubt the morality of slavery pretty early on, in the 1750's. He'd freed all of his by the time he returned from France in 1785. What's more, he helped to form the Philadelphia Society for the Relief of Free Negroes Unlawfully Held in Bondage, usually called the Abolition Society, and during the last years of his life was its President. He tried- very hard- to get slavery abolished, in the first few years of the Republic but failed. If he had been younger, not in failing health, it's possible he could have done more.

There were some of the F.F's who depended on slaves and later freed some of them in their wills, like Washington. But their attitudes were somewhat contradictory. Washington seems to have had no doubts about owning slaves- he liked farming, and they were farm labor he needed, so though he freed some slaves he liked slavery. John Jay's father had owned slaves, and John jay himself owned slaves, but Jay strongly supported abolition- despite his stance, he seems to have decided that he himself should buy and work a slave for a bit, to pay off their "debt", then free them- perhaps, like Washington, following the laws requiring him to first endow them with a means to live. Madison fully admitted that the ideals of the Declaration and slavery were incompatible, and hoped for abolition but, very much the politician, saw it only as a political problem and never seems to have hit upon a simple workable political solution for implementing it. Like Jefferson, he saw slavery as an evil and also did not free his own slaves in his will- and, unlike Jefferson, his slaves were actually legally his property, not mortgaged. Both Madison and Jefferson also supported the Northwest Ordinance that banned slavery from the new western territories: so, clearly they felt that slavery was bad in principle, but exempted themselves from following that principle.

These hopes of gradual abolition were not unusual among southerners at the time, at least in Virginia. It would not be until the invention of the cotton gin and the industrial revolution in British textile-making later in the early 19th c. that slavery would become so immensely profitable and economically indispensable for the southern ruling class as to make such views very rare..