The II Corps is a military formation that has been used by various armies throughout history, notably in the United States Army during the American Civil War and both World Wars. It typically consists of multiple divisions and is designed to operate as a significant tactical unit on the battlefield, coordinating various combat and support elements. In the American Civil War, the II Corps was known for its role in key battles such as Gettysburg and Antietam. It was commanded by notable leaders like Daniel Sickles and Winfield Scott Hancock, contributing to its reputation for effective leadership and strategic importance in the Union Army's efforts.