[morelisp]

heavyset_go has provided a good source for my more general statements but I want to specifically address

> police forces in the Northern states are obviously not derived from "slave patrol remnants"

This is a common misconception that the north was "free" even as the south kept enslaving people. It's true that the north also had other economic forces influencing its policing, but the Fugitive Slave Acts gave plenty of legal cover for anyone wanting to make a buck by finding "escaped slaves" (often just whatever black people they found) in the north.