Old Northwest War (January, 1790 - August, 1795) - Called the Miami Campaign by the U.S. Military, this war erupted In the late 1780's as settlers wished to push into the "Old Northwest," now present-day Ohio and Indiana. However, hostile Indians, chiefly the Miami and Indiana tribes, resisted this expansion. Three separate expeditions of military forces were soon sent in to remove this obstacle to expansion.

In the fall of 1790 a force of 320 regular army troops, along with 1,000 Kentucky and Pennsylvania militiamen led by Brigadier General Josiah Harmar, moved north from Fort Washington (Cincinnati), but were badly defeated in two separate engagements on October 18th and 22nd in the vicinity of present-day Fort Wayne, Indiana.

Congress then commissioned Governor Arthur St. Clair of the Northwest Territory as a Major General. St. Clair then collected a force of about 2,000 troops who advanced north from Fort Washington in September, 1791, building a road and forts as it progressed. However, on November 3-4, the troops were surrounded by the Indiana tribe, who killed 637 of St. Clair's men and wounded another 263. The defeated troops returned to Fort Washington.

Congress reacted to these disasters by doubling the authorized strength of the Regular Army in 1792 and appointed Anthony Wayne to succeed St. Clair. Major General Wayne joined his troops near Pittsburgh, Pennsylvania in June, 1792. Moving his men to Fort Washington in the Spring of 1793, Wayne reorganized the soldiers and began extensive training programs. After trying unsuccessfully to negotiate peace with the Indians, the troops moved north once again in October, building additional fortifications along the way. In the spring of 1794, they built Fort Recovery at the site of St. Clair's defeat. In June, the fort was attacked by the Indians, but the newly reorganized and trained soldiers forced them to retreat. The following month, Wayne moved forward with a force of some 3,000 men, pursued the Indians confronting them on August 15 near Fort Miami (a British outpost.) After a stand-off of several days, the conflict ended after a two-hour battle on August 20, 1794 that the Indians defeated. Wayne's troops then destroyed the Indian villages. The following year, in the Treaty of Greenville, the Indians of the region ceded their lands in southern and eastern Ohio and the way was opened for rapid settlement of the Northwest Territory.

Tippecanoe (September 21 - November 18, 1811) - The spread of settlements in the "Old Northwest" created additional tension with other tribes. In 1804, Shawnee Chief Tecumseh, along with his his medicine man brother, the Prophet, gained British backing and began serious efforts to form a new Indian confederacy in the Northwest. Governor William Henry Harrison of the Indiana Territory rejected Tecumseh's demand that settlers be kept out of the region. In the summer of 1811 Harrison, with the approval of the War Department, undertook to break up the confederacy before it could organize a major attack against the settlements.