Why did frontier disturbances lead the United States to increase its standing army after 1783?

Following the American Revolution, the United States initially disbanded its army, leaving only a tiny force to guard military stores. However, this policy was quickly reversed due to persistent frontier disturbances.1

The primary driver for increasing the standing army was the need to address escalating conflicts with Native American tribes in the Northwest Territory. These tribes, organized as the Northwest Indian Confederation, resisted the encroachment of American settlers on their lands. The U.S. government viewed these territories as vital for expansion, intending to provide land to Revolutionary War veterans as compensation for their service.123

Early attempts to pacify the region using small forces and militia proved disastrous, most notably during Saint Clair’s Defeat in 1791. These failures demonstrated that a larger, better-trained regular force was necessary to secure the frontier. Consequently, President George Washington persuaded Congress to expand the regular army, eventually leading to the creation of the Legion of the United States under Maj. Gen. Anthony Wayne, which successfully secured the region following the Battle of Fallen Timbers.123