The M3 Lee was America's first mass-produced combat tank. Its unusual configuration of hull-mounted 75 mm gun and turret-mounted 37 mm cannon was a result of the rush to get the vehicle in production following Nazi Germany's rapid advances in Europe. Following heavy British tank losses in France, the Commonwealth turned to the US to bolster their tank stocks, and the M3 was adapted, through the use of a different turret style, to fill this need. Later, as more-advanced tanks became available, notably the M4 Sherman, the M3s were adapted to fill other roles. This book chronicles the development and use of these vehicles from concept to combat. Through dozens of archival photos, many never before published, as well as detailed photographs of some of the finest existent examples of surviving vehicles, these iconic armored fighting vehicles are explored, and their history is explained.