Birge was born at Hartford, Connecticut at the opening of the Civil War he organized the first state regiment of three-year troops — the Fourth Connecticut Volunteers — in which he was appointed major. After service in Maryland and Virginia he was commissioned colonel of the Thirteenth Connecticut infantry regiment in 1861 and in 1862 was placed in command of the defenses of New Orleans. In December of the latter year he was appointed to the command of a brigade, which he retained through the first Red River campaign and at the siege of Port Hudson. He was raised to the rank of brigadier general in September, 1863, served in the second Red River expedition, and subsequently commanded at Baton Rouge. In 1864 he was assigned to the command of the second division of the Nineteenth Corps. He participated in the battles of General Sheridan's campaign in the Shenandoah valley, and in February and March, 1865, was appointed to the command of the defenses of Savannah. In the same year he resigned, with rank of major general of volunteers.