Auto-Ordnance Company was made by John T. Thompson in August 1916 fully backed by financial backer Thomas Ryan. In 1915 Thompson had found the Blish Lock patent of Administrator John Blish, which was the working standard of the primary models of the Thompson submachine gun and the Thompson Auto rifle. In return for portions of the recently established organization Blish consented to give Thompson his patent. Thompson recruited two plan engineers Theodore H. Eickoff and Oscar V. Payne. The specialists discovered that the Blish lock plan, which was a deferred blowback activity, was insufficient with the .30-06 bullet however extremely compelling with the .45 ACP gun round. The introduction of the Thompson submachine gun occurred when Thompson had the possibility of a “channel sweeper” or “channel brush”. The primary short run creation model was 1919, past the point of no return for use in Universal Conflict I.

Thompson originally showed the submachine gun plan to the US government, yet it turned into a gun for policing involving in the military was put. The underlying creation of the Model 1921 was by Foal. After the Thompson submachine gun got the epithet “Submachine Gun” in the famous press, Thompson went to the brand name office to safeguard the moniker.