The Treaty of Paris in 1783 gave the United States possession of a large unsettled territory extending west to the Mississippi River. Spain controlled Florida, Louisiana, and access to the Mississippi River, and until 1796 Britain retained possession of Forts Oswegatchie, Oswego, and Niagara in upstate New York and Forts Miami, Detroit, and Michilimackinac in the Northwest. The Confederation government lacked the military strength to stop white settlers from pouring into Indian lands or to stop Native Americans, often supported by the British and Spanish, from resisting the invasion of their lands. Yet Congress boldly claimed sovereignty over Indian lands by virtue of their victory over Britain and imposed treaties on several tribes. Both white settlers and Native Americans ignored the treaties, and the resulting conflict was passed on to the new federal government in 1789. The Washington administration, hoping to avoid costly Indian...