Famous People of the Civil War Ulysses Simpson Grant served effectively with Zachary Taylor's army at Monterey during the Mexican war. Right when the war began Grant obtained a position on the staff of General George McClellan. During the war he showed courage in both physically and morally manners. In February 1862 Grant captured Fort Henry and Fort Donelson with help from the Federal navy. In October he was appointed commander of the Department of Tennessee, and told to take Vicksburg, Mississippi. Earl Van Dorn captured Grant's base at Holly Springs and he had to retreat. In 1864 Grant was promoted to lieutenant general a