Explanation: During the American Revolution, and in the lead-up to it, the American colonists' position wherein American colonists were denied representation in the British government was often compared (by said colonists) to slavery.
The thing is, uh, many of them were literal slavers themselves, running, for that matter, one of the worst systems of slavery in human history at that. No mean feat, considering the already-low bar for slavery as a system.
Of the Founding Fathers as they're generally recognized, four of the seven became abolitionists, either before or during the American Revolution (John Jay, Ben Franklin, Alexander Hamilton, John Adams). One turned against slavery as an institution, but did not come out publicly in favor of abolition before his death (Washington). One had negative feelings on slavery, but also negative feelings on Black people (Jefferson). One was an unrepentant slaver (Madison).