Fort Hamilton was a log stockade completed Sept. 30, 1791, as a fort of deposit, or supply center, for the army of Gen. Arthur St. Clair, which was advancing toward Kekionga, a Miami settlement near the site of present Fort Wayne, Ind. St. Clair named the fort after Alexander Hamilton, then the secretary of the treasury in President George Washington's cabinet. Earlier, St. Clair had named the fort at Cincinnati in honor of the president, Fort Washington. During his 1791 campaign, he named a third fort in honor of Thomas Jefferson, the secretary of state. Fort Hamilton's location on the east bank of the Great Miami River, at a ford on an old Indian trail, was selected by Lt. Col. William Darke, for whom Darke County is named. A Native American army led by Little Turtle, a Miami chief, defeated St. Clair's army Nov. 4, 1791, in a nameless battle at what later became Fort Recovery, Ohio.
Gen. Anthony Wayne assumed command of the frontier army in 1792 and ordered Fort Hamilton nearly doubled in size. It was a key supply post during Wayne's campaign which ended in victory Aug. 20, 1794, at the Battle of Fallen Timbers, near Toledo. Wayne negotiated the Treaty of Greenville with Little Turtle and other Indian leaders in the summer of 1795, and, as a result, Fort Hamilton was abandoned by the army. It became the nucleus for what became the City of Hamilton. At first, the small community around the site of the fort was called Fairfield, but it was soon changed to Hamilton. On the present Hamilton street system, the expanded fort would have extended along Monument Avenue from about Market Street on the north to between Court and Ludlow streets on the south, and east from the river to about Front Street.