"With Dred Scott as law that would be a wise destination"
There are a lot of laws on the books in this country that I do not like such as paying income taxes and 55 mile per hour speed limits on 4 lane highways. Does your remark mean that it is alright for me to disobey these laws if I find them immoral?
Only a minority of northerners supported the underground railroad. It was a "secret" society because it was illegal. It was as illegal as bank robbery or as illegal as helping someone excape from a prison. We are no different today. By definition of law, a supreme court ruling like Dred Scott, we do not now reconize an unborn baby as a human being. And therefore it can be discarded as we will. By definition of law in 1860 slaves were property and could be bought and sold as such. Should those of us who believe that unborn babies are Human, start a war to change that law? Or should we do it by legal legislative measure?
Blacks stood out like modern day illegal immigrants in the north. And like you point out the Blacks could only recieve the total freedom if they made it all the way to Canada. That was because Canada had followed the English plan of emancipation. Which was the plan of abolishion supported by most of the southerners at the time.