"In his remarkable and challenging book The Crooked Path to Abolition, he makes the case that there were effectively two constitutions written in Philadelphia that summer of 1787, one proslavery and one antislavery, which would be in conflict with each other for more than the next fourscore years."

https://www.nybooks.com/articles/2023/06/08/the-two-constitutions-abraham-lincoln-james-oakes/