What was the act that didn't allow the colonists to settle further than the appleachian mountains?

The act that restricted colonial settlement west of the Appalachian Mountains was the Proclamation of 1763. Issued by the British Crown, it aimed to stabilize relations with Native Americans by preventing colonists from encroaching on their lands. The Proclamation angered many colonists, as it limited their expansion and access to new territories, contributing to growing tensions between Britain and its American colonies.