Haig was born in Pennsylvania and had two siblings. His father died when he was young and he was raised by his mother. Haig went to college at Notre Dame University for two years before switching to the United States Military Academy. He later attended Columbia and Georgetown to get his masters. While in the army, he served in the Korean War in several major battles. He served as a commander in the Vietnam War. At one point, his helicopter was shot down and he saw two days of violent hand-to-hand combat. He was awarded the Purple Heart and Distinguished Flying Cross for his notable bravery in wartime.