SUMMARY Ambrose E. Burnside was a major general in the Union army during the American Civil War (1861–1865). Instantly recognizable for his bushy sideburns (the term itself is derived from reversing his last name), Burnside was one of four men to command the Army of the Potomac in Virginia. Offered the job twice previously—following George B. McClellan‘s failed Peninsula Campaign in 1862 and following the Second Battle of Manassas later that summer—he turned it down, citing his own lack of experience and encouraging his peers and, subsequently, historians to question his self-confiden...