What prohibited settlement beyond the Appalachian Mountains?

The Proclamation of 1763 is the correct answer because it was explicitly designed to regulate colonial expansion and prevent settlers from moving west of the Appalachian Mountains. This decree was issued by the British Crown following the end of the French and Indian War as a means of stabilizing relations with Native American tribes and avoiding further conflict over land. By restricting settlement in this area, the crown aimed to manage colonial growth and ensure that the vast territories gained through the war could be properly controlled and administered.

The significance of this proclamation was that it communicated the British government's intention to maintain a buffer zone between colonists and Native Americans, acknowledging the complex dynamics of land ownership and sovereignty. The colonial response was mixed, with many settlers feeling constrained by the terms and actively defying the proclamation, further sowing seeds of dissent that would contribute to revolutionary sentiment in the years to come.