Clark's major military achievements occurred before his thirtieth birthday. Afterward, he led militia in the opening engagements of the Northwest Indian War, but was accused of being drunk on duty. He was disgraced and forced to resign, despite his demand for a formal investigation into the accusations. He left Kentucky to live on the Indiana frontier but was never fully reimbursed by Virginia for his wartime expenditures. During the final decades of his life, he worked to evade creditors and suffered living in increasing poverty and obscurity. He was involved in two failed attempts to open the Spanish-controlled Mississippi River to American traffic. After suffering a stroke and the amputation of his right leg, he became an invalid. He was aided in his final years by family members, including his younger brother William, one of the leaders of the Lewis and Clark Expedition. He died of a stroke on February 13, 1818.