Service in the Northwest Indian War
Enlisting for service as a captain in the Northwest Indian War in 1791, Adair was soon promoted to major and assigned to the brigade of James Wilkinson. On November 6, 1792, a band of Miamis under the command of Little Turtle encountered Adair and about 100 men serving under him on a scouting mission near Fort St. Clair in Ohio. When the Miami attacked, Adair ordered Lieutenant (and later governor of Kentucky) George Madison to attack their right flank while Adair led 25 men to attack the left flank. (Adair had intended for a subordinate to lead the charge, but the officer was killed before Adair could give the order.) The maneuver forced the Miamis to fall back and allowed Adair's men to escape. They retreated to their camp and made a stand, forcing the Miamis to withdraw. Six of Adair's men were killed; another four were missing and five were wounded. Among the wounded were Madison and Richard Taylor, father of future U.S. President Zachary Taylor.
Recognizing his bravery and fighting skill, Adair's superiors promoted him to lieutenant colonel. He was assigned to the command of Charles Scott, who would eventually serve as Kentucky's fourth governor. He assisted in the construction of Fort Greeneville in 1794, forwarding supplies to Anthony Wayne during his operations which ended in a decisive victory at the Battle of Fallen Timbers.