Was in the battles of Grangeville, Manasas, South Mountain, and Antietam. Brevetted major-general of volunteers for gallant and meritorious conduct at Antietam. He held an important command at the battle of Fredericksburg, where he was severely wounded. Was brevetted lieutenant-colonel U.S.A. for gallant and meritorious services at the battle of Fredericksburg. Was severely wounded at the battle of Gettysburg while commanding the Second Corps, and brevetted colonel U.S.A. for gallant and meritorious service in that action. He also held an important and responsible command in the Richmond campaign, and was brevetted brigadier-general U.S.A. for gallant and meritorious services at Spotsylvania. Was commissioned major-general of volunteers June 7, 1864. Brevetted major-general U.S.A. for gallant and meritorious conduct in the capture of Petersburg. Mustered out of the volunteer service June 15, 1866, and commissioned a colonel U.S.A. July 28, 1866. Promoted to brigadier-general U.S.A. July 10, 1885, and appointed to the command of the district of the Rocky Mountains. He commanded the column that rescued Reno from the Sioux Indians in June, 1876. An officer who has served with him several years, and knows him intimately, says: "He is an able writer and deep thinker, a thorough soldier, and no politician; honest, strict on duty, and genial and kind off duty. He is brave as a man can be in battle. A true and loving husband, a kind father, and the truest kind of a friend. A thorough sportsman, temperate, modest, and as careful of the wellfare of the humblest enlisted man as of his chief of staff." Capt. Constant Williams, in a private letter to the author, under date of December 23, 1888, says: "I wish to bear testimony of the noble bearing of General Gibbon during the whole time the fight was in progress, under the most trying circumstances. His coolness and utter indifference to danger were so marked, and so admirable, that I have ever since that day taken him as my model for a commander."