whites were still being enslaved by African nations at late as 1877? Listen to the USMC Hymn and when it gets to "to the shores of Tripoli" it was referring to the Barbary pirates and how we sent US Marines to stop them from capturing and enslaving US citizens as well as those from other countries.
The point is slavery has existed in all times and in all places. You cannot single out the US and say, our country was founded on slavery and needs to pay reparations or as reason to disassemble all the founding principles of this country while the rest of the world is exempt. We were paramount in the dissolution of all slavery. It still exists today but thanks to Western Civilization it is only the the shadows of this world and is no longer an acceptable world ideology (expecept for Leftist who won't embrace it publicly but through policies and practices allow or encourage it).
Fun fact, the US had fewer African slaves than Africa had white slaves during the time period of 1619 to 1865. Things that make you go hmmmm.