John Bankhead Magruder was an American and Confederate military officer. A graduate of West Point, Magruder served with distinction during the Mexican–American War (1846–1848) and was a prominent Confederate Army general during the American Civil War (1861–1865). As a major general, he received recognition for delaying the advance of Maj. Gen. George B. McClellan's large force, the Army of the Potomac, during the 1862 Peninsula Campaign, as well as recapturing Galveston, Texas the following year.

The Peninsula campaign of the American Civil War was a major Union operation launched in southeastern Virginia from March to July 1862, the first large-scale offensive in the Eastern Theater. The operation, commanded by Major General George B. McClellan, was an amphibious turning movement against the Confederate States Army in Northern Virginia, intended to capture the Confederate capital of Richmond. McClellan was initially successful against the equally cautious General Joseph E. Johnston, but the emergence of the more aggressive General Robert E. Lee turned the subsequent Seven Days Battles into a humiliating Union defeat.