The Gallager carbine was designed by Dr. Mahlon J. Gallager, a Southerner by birth, and manufactured under license by Richardson & Overman in Philadelphia. The first two versions were widely used during the Civil War by the Union cavalry though they suffered from extraction problems like many of the breech loaders from the era. This example is one of 5,000 of the final cartridge model delivered near the end of the main fighting in the Civil War. It has a "pinched" blade front sight, notch and folding leaf rear sight, "GALLAGER'S PATENT/JULY 17TH 1860" and "MANUFACTD BY/RICHARDSON & OVERMAN/PHILADA/24163" on the lock plate, matching assembly numbers ("127"), and a smooth stock with blued patch box, saddle ring bar, and ring. The top of the barrel behind the rear sight is stamped with a "J.M.D." inspector stamp. The left side of the stock just behind the sling bar has a "WHB" cartouche (inspector William H. Barber or Bulkey).

Exceptionally fine. The barrel retains 85% plus of the lightly fading original blue finish, the patch box door retains more than 25% of the original blue blended with brown patina, and the remaining parts retain 70% of the somewhat muted case colors. The colors remain especially vibrant below the bolster. The stock is excellent with a sharp cartouche, raised feathered grain, and mild scratches and dings consistent with handling and storage. Mechanically excellent. The markings are crisp.