One big part of slavery in the US was the internal "migration", the movement of slaves from the Atlantic Coast colonies to the newer states of MS, AL, AL, AR, mostly it seems by sale to slave traders.
There are differences in the societies in different parts of the New World, partially from differences in Spain, France, and Britain, partially from differences in the crops being grown, and partially the climate/health conditions. I know that; what I didn't think about until today was the difference in size. The US and Brazil are big countries, while the Caribbean islands are much smaller. So in the US slaves who gave trouble could be threatened with being sold to slave traders or "down river". On the other hand the slave population multiplied by natural increase in the US, less so or not so at times elsewhere.
So the question I have is whether historians can find a difference in what might be termed "mobility", except it connotes choice. What was the probability that a slave born in 1770 in Virginia would die 200+ miles away versus the same probability for a slave in the sugar islands of the Caribbean? And, if there's a difference, what impact was there on the societies?