Organized at St. Louis March 18, 1862, by consolidation of 5th United States Reserve Corps, Voerster's Company Sappers and Miners, Giester's Company Pioneers and Winkelman's Company Pontoneers. Guard bridges on Iron Mountain Railroad and duty in South east Missouri until July. At Cape Girardeau, Mo., until November, 1862. Company "F" in District of Mississippi July, 1862. Companies "A" and "I" transferred to 25th Missouri Infantry, and Companies "H" and "K" to 27th Missouri Infantry. Companies "B," "C," "D," "E," "F" and "G" mustered out November 22, 1862.