Not one bit. The mere fact that the Constitution itself lays out explicitly a process of amendment would render any such assertion invalid on it's face.
In 1860 almost all northerners, and all northern politicians, agreed that the Union had no right to interfere in slavery within a state. To be fair, a good many of the pols were probably lying, much like Obama claiming to be against gay marriage as recently as two years ago.
There was contention between the Northern and Southern states, even early on. Who's idea was it to only count slaves as 3/5 of a person, and who benefitted from that?
Why should property be counted at all for purposes of representation?