Approximately 132,000 of these New Model Army revolvers were manufactured from 1863 to 1875. This revolver would eventually become one of the most widely issued to Union troops during the Civil War, especially after a fire at the Colt factory in 1863, which put their rivals' revolver production temporarily to an end. It has standard markings including government inspection marks, "BH" cartouche on the grip, and matching serial number on the frame, trigger guard, and left grip panel. The period replacement barrel is numbered "64277" and a faint name is period carved in the bottom of the left grip panel, possibly "G. NYMON".