He distinguished himself in the early days of the War of Independence. Moving to Kentucky, he became a principal figure in the confused politics of the developing south‐west. He re‐entered the army in 1791 and went on to serve as governor of the Louisiana Territory (1805–06). While there he became involved with Aaron Burr’s conspiracy, but betrayed the latter and acted as prosecution witness in the subsequent treason trial. The failure of his campaign to capture Montreal in the early stages of the War of 1812 led to his removal from command.