Few firearms have earned the mystique that the Thompson submachine gun has enjoyed for nearly a century. The long association that the "Tommy Gun" has had with gangsters, G-men and G.I.s has made it a movie star, a prized collectible, and an American icon. The gun's genesis dates back to World War I when retired General John T. Thompson sought to develop a lightweight, fast-firing rifle that U.S. troops could use as a "trench broom" to break the stalemate of trench warfare. Thompson believed recoil or gas operated weapons were too heavy and complicated for this role and sought a...