Company "A" was organized at Yankton, Dakota Territory in April of 1862. Company "B" was organized at Sioux City, Iowa on March 31, 1863. This unit was assigned to duty in the District of Iowa and Dakota Department of the Northwest, defending frontiers and operating against Indians. Participated in Sully's Expedition against hostile Sioux Indians in Dakota Territory from July 25th to October 8, 1864, with engagements at Tahkaha-kuty on July 28th and at Two Hills, Badlands, Little Missouri River August 8th - 9th. Company "A" mustered out on May 9, 1865. Company "B" mustered out on November 15, 1865.