The Third Corps was a military unit in the United States Army during the American Civil War. It was established in 1862 and played a significant role in several key battles, including the Battle of Gettysburg and the Battle of Chancellorsville. The corps was known for its organization and effectiveness in combat, often engaging in critical maneuvers that influenced the outcomes of battles. Commanded by notable leaders such as Major General Daniel Sickles and Major General George Meade, the Third Corps was part of the Army of the Potomac. It consisted of multiple divisions and was instrumental in various campaigns throughout the war, contributing to the overall efforts of the Union forces against the Confederacy.