 He was promoted to captain on June 8, 1836, and fought in the Seminole Wars in Florida from 1839 to 1842.At the start of the Mexican–American War, he received a brevet promotion to major for his "gallant and distinguished conduct" in the defense of Fort Brown, Texas.He fought in the Battle of Monterrey and the Siege of Veracruz, which he then governed as military commandant for four months.