Slavery was legal in every state at the time of the American Revolution. It was not abolished by the State of New York until the late l820's, little more than 30 years before the Civil War.
By the grace of God and the wisdom of their founding fathers, the American people did finally manage to expunge this horror (from America; it still exists in other parts of the world).
Their savior was the U.S. Constitution and The Declaration of Independence--two of the most sacred and subversive documents ever created by mankind.
No wonder tyrants the world over tremble before the Constitution and The Declaration of Independence! No wonder tyrants fear America so!
I know I might be a couple of years late about the responses but I had to comment on your response.
Surely the slavery was not the only issue in the civil war but it was the main cause of the Civil War.
How about you go back to the history books and get back to us!