The Mann's Patent Cartridge Box is one of the more interesting and scarcer late-war Federal accouterments, representing the U.S. Army's effort to improve the infantryman's field equipment during the final years of the Civil War.

Colonel William D. Mann of Detroit, Michigan, patented his improved cartridge box in late 1863, and the patent was reissued on June 7, 1864, the date found embossed on the front flap of surviving examples. The design was intended to simplify a soldier's equipment by combining the functions of the standard cartridge box, cap pouch, and pistol cartridge pouch into a more compact and accessible arrangement. Most surviving examples were manufactured by Emerson Gaylord of Chicopee, Massachusetts, one of the Union Army's premier contractors for leather accouterments. Gaylord supplied enormous quantities of cartridge boxes, belts, cap pouches, and other equipment to the U.S. government throughout the Civil War, and his workmanship is regarded among the finest produced during the conflict. The embossed marking, "Patent Reissued June 7, 1864 – E. Gaylord Maker, Chicopee, Mass.", identifies one of these desirable late-war contract pieces.

Because relatively few Mann's Patent boxes were produced and issued compared to the millions of standard Federal cartridge boxes, they are considerably scarcer today and are highly sought after by collectors of advanced Civil War accouterments.