When did colonists first start moving west of the Appalachian mountains?

Colonists began moving west of the Appalachian Mountains in significant numbers after the French and Indian War, which concluded in 1763. The Proclamation of 1763 initially restricted westward expansion, but many settlers ignored it, seeking new land and opportunities. The westward migration accelerated in the late 18th century, particularly after the American Revolution, as new territories became available for settlement.