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.

Fine with an old protective coat of varnish overall, retains 85% plus original blue finish on the barrel and patchbox, and 60% plus original case colors concentrated mostly on the lock and right of the frame with some slight fading on the left, with scattered patches of moderate surface corrosion and light freckling, and sharp edges and markings in the metal overall. Stock is very good with areas of discoloration, and some scattered dents and scratches. Mechanically excellent.