The British had promised the native peoples that they could keep all of the land to the west of the Appalachians.
However, after the Revolutionary War, the British were no longer in control, and the newly organized American state did not share that opinion at all. In fact, it actively began to encourage people to move across the Appalachians to the Ohio valley.
By about 1800 a tenth of all Americans lived west of the Appalachians.
