 Stationed briefly in Pensacola, Florida, he was transferred with his unit to East Tennessee and later central Kentucky, where he fought and was later captured at the Battle of Fort Donelson.After being released in a prisoner exchange, he was promoted to the rank of brigadier general and sent to West Tennessee, where he assumed command of a mixed brigade of Mississippi and Tennessee soldiers.Winning distinction at the Battle of Coffeeville, Baldwin would later participate in the battles of Port Gibson and Champion's Hill, as well as taking part in the Vicksburg Campaign.