Nothing said in 1857 had one damned thing to do with what was in the minds of different people who wrote the Bill of Rights in previous generations.
So most of those slave uprisings do not count , the environment changed a lot in those seventy years.
But doesn't this make it even less likely that runaway slaves were a major concern when the constitution was written? There were less slaves then and the underground rail road was not in operation yet.
The way I understand it , slavery was never really a good thing , but in our version of it it tended to grow gradually worse, and racism along with it.