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 ring bar, and saddle ring.

Very good with 30% original blue finish on the barrel with the balance having turned to a smooth brown patina with scattered light surface pitting, 30% original case colors concentrated on the right side of the frame with scattered mild freckling and gray patina on the balance. Stock is good with numerous scattered scratches and dents. Mechanically fine.