The Gallager carbine was designed by Dr. Mahlon J. Gallager, a Southerner by birth, and manufactured under license by Richardson & Overman in Philadelphia where Gallager had a dental practice. Reportedly 17,728 Gallager carbines were manufactured in three different variations. It has a pinched blade front sight, notch and folding leaf rear sight, blued barrel and casehardened frame, lock plate marked "GALLAGER'S PATENT/JULY 17Th 1860" and "MANUFACTd BY/RICHARDSON & OVERMAN/PHILADa" above the serial number, smooth walnut stock with blued patch box, saddle bar and ring. An old collection sticker numbered "27" is on top of the stock ahead of buttplate.