And..
Early 1700s the Virginia colonial House of Burgesses, which had a variable attitude about slavery, attempted to outlaw the practice but the British government overruled the attempt.
I wish I could cite the source on this claim but I only recall it from a Patrick Henry biography.
Thank you for reminding me of this. I can give you the source.
https://books.google.com/books?id=OKE6AAAAcAAJ&pg=PA456#v=onepage&q&f=false
The King’s veto of colonial abolition moves used the following language:
“upon pain of the highest displeasure, to assent to no law by which the importation of slaves should be in any respect prohibited or obstructed”