Which geographic feature did the British government use in 1763 as a boundary to restrict the westward settlement of American colonists?

The Proclamation Line of 1763 was a British-produced boundary marked in the Appalachian Mountains at the Eastern Continental Divide. Decreed on October 7, 1763, the Proclamation Line prohibited Anglo-American colonists from settling on lands acquired from the French following the French and Indian War.

Explanation:

they wanted the u.s. to fight on the side of the central powers.