The Proclamation of 1763 was a royal proclamation rather than parliamentary legislation. It was intended to restrain American colonial expansion west of the Appalachians, thus reducing the risk of conflict between whites and Native peoples who resisted incursions on their lands (and thus avoiding the cost of maintaining British frontier garrisons to protect settlers.) It was largely ineffective, but its main consequence was to convince Native peoples to identify the British not as benefactors, but certainly as preferable to the Americans as allies in the American Revolution. Only a handful of Native peoples, most of whom lived in areas already surrounded by white settlements, sided with the American revolutionaries.
The Northwest Ordinance, established under the Articles of Confederation, promised to practice "good faith" toward Native Americans in the Northwest Territory, but by establishing a process of expansion and incorporation in the Union, it encouraged a process that stripped Native peoples of their lands. The Bureau of Indian Affairs, created by the federal government to oversee treaty arrangements and to foster the "management" and assimilation of Native Americans, ultimately became charged with overseeing the implementation of the Indian Removal Act. This law, passed in 1830, led to the "removal" of thousands of Native Americans from the American South and the Northwest by creating an Indian Territory in modern Oklahoma. It also empowered the state governments to negotiate treaties to facilitate this process. Its effect was to leave only vestiges of once-powerful Native peoples in the South in particular.