The highly effective "Long Tom" heavy field gun could fire a 100 lb shell over 14 miles (24 km). Officially known as the "155mm gun M1A1 with M1A1 carriage and M5 limber," these famous artillery pieces, alongside their related 8-inch howitzer M1 versions, formed the backbone of U.S. Army heavy field artillery units during both World War II and Korea. These towed artillery weapons initially used the Mack NO 7-1/2-ton 6x6 as a prime mover, which was also agmented by the M4 high-speed tractor during the later stages of World War II. Eventually Long Toms were upgraded to the M125 10-ton 6x6 prime mover and proved to be remarkably mobile for towed heavy artillery. With their superior combinations of long range, pin-point accuracy, and massive firepower, these remarkable WWII artillery pieces served well into the Cold War-era. Featuring 227 archival photos, this new 80-page book documents the development and combat deployments of these iconic WWII weapons, as well as their essential caissons and heavy prime movers.