August 9, 1861

Benjamin Mayberry Prentiss was promoted to brigadier general in the Union army and was ordered to take command of an area in northern Missouri. Prentiss most notably served as the Federal commander at the 1863 Battle of Helena. After his successful defense of Helena (Phillips County), Prentiss was not given a new command when Federal forces in the Mississippi River Valley reorganized that autumn. Ordered to report to Washington DC to await an assignment, he instead resigned his commission.