The Peninsula Campaign (also known as the Peninsular Campaign) of the American Civil War was a major Union operation launche in southeastern Virginia from March through July 1862, the first large-scale offensive in the Eastern Theater. The operation, commanded by Maj. Gen. George B. McClellan, was an amphibious turning movement intended to capture the Confederate capital of Richmond by circumventing the Confederate States Army in northern Virginia. McClellan was initially successful against the equally cautious General Joseph E. Johnston, but the emergence of General Robert E. Lee changed the character of the campaign and turned it into a humiliating Union defeat.