Which mountain chain acted as a natural boundary between the 13 colonies and the Ohio river valley?

As a natural boundary between the French and 13 British colonies, the Appalachian Mountains acted. It would appear that both groups would stick to their own side, but an area called the Ohio Valley area was claimed by both the British and French. West of the Appalachians, surrounding the Ohio River across to the Mississippi River, was the Ohio Valley area.

it granted civil rights to african americans.