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.

Virginia, officially the Commonwealth of Virginia, is a state in the Southeastern and Mid-Atlantic regions of the United States between the Atlantic Coast and the Appalachian Mountains. The state's capital is Richmond and its most populous city is Virginia Beach, though its most populous subdivision is Fairfax County, part of Northern Virginia, where slightly over a third of Virginia's population of 8.72 million live as of 2023.