In 1916 the Auto-Ordnance Corporation was established to create a new automatic rifle for the armed forces. The innovative design was to incorporate a "new" principle for locking the bolt and breech of the firearm, based on the "Blish Principle of Metallic Adhesion."

An Engineering Department was established in Cleveland, Ohio, to work with the Warner-Swasey Co. General John T. Thompson put two very young engineers in charge of design and development: Theodore Eickhoff, a graduate of Purdue University, who had worked for the US Ordnance Department since graduation, and Oscar Payne, a self taught practical tinker and draftsman. The Engineering Department worked for two years with limited success to develop an automatic rifle using the "Blish Locking System." However, during one of the later tests, the new .45 ACP cartridge was found to function flawlessly with the new breech locking system.

With the full backing of General Thompson, who had been instrumental in the original development of the .45 ACP cartridge and had overseen the development of the Model 19 11 Colt, the design team developed a series of submachine guns known as the Thompson Submachine Guns, Model of 1919s.

The Model of 1919 Thompsons were not a single production design, rather a series of experimental prototypes. Each serial numbered receiver is a slightly modified version of the proceeding receivers. The Model of 1919 Thompsons are divided into two different series of designs, with the second series divided into four families, each subsequently divided into several submodel designs. The total number of Model of 1919s produced of all types is believed to be about 40. Of these 40 prototypes only 11 are known to exist today, with only FIVE prototypes known to be in private hands.

The first Model of 1919 was called the "Persuader." This Thompson was designed to fire the .45 ACP cartridges from a cloth belt of ammunition. However, the design proved to be an unreliable means of supplying the rapid fire Persuader. At best engineers were able to fire only seven rounds before a malfunction of the feed system stopped the action. (This Thompson is on display at West Point Military Museum.)

Further development lead to the second series of 1919s known as the "Annihilators." The first of these was a work bench "Annihilator Trial Mechanism." This was used to validate a design based on improvements from the "Persuader." The "Annihilator I, Serial Number 1" Model of 1919 was the first Thompson design to feed ammo from a drum magazine and a box magazine. (This Thompson is in the West Point Military Museum.)

The next Thompsons were the "Annihilator II," Serial Numbers 2 and 3, Model of 1919s. These were the first Thompsons demonstrated to the public. Serial Number 2 was demonstrated in New York, New York in March of 1919, test firing 18,000 rounds, without a malfunction. (Serial Number 2 is in the West Point Military Museum.) Serial Number 3 was retained at the Engineering Department in Cleveland and was used for testing of a bayonet mount, Maxim suppressor and optical sights.

These two 1919s lead to the final family known as the "Annihilator III" Thompsons. This family is divided into at least five separate submodel groups. The first of these groups was the "Annihilator III, Model Cs" of which there were originally 10 sets of components built, but not all finished into Model Cs. Only two known Model C, l919s are known to exist today: Serial Number 6 (In the Rock Island Museum) and Serial Number 7.

CASE NUMBER ONE - The contents of this case are the standards by which all submachine gun designs were measured from 1919 to 1950.

BLISH PISTOL - This is the patent demonstration model built by Capt. John Blish, who is the American patent holder and inventor of the Blish Principle of Metal Adhesion. Only patent model was ever created. The principle, simply stated is that two different metals will adhere to one another under high pressure, but will move against each other (ie: slide) when this high pressure is removed. The pistol was used to demonstrate his patent application and later to demonstrate to the engineers of Auto-Ordnance how his theories worked. The pistol uses a .30 (7.65 mm) Luger barrel attached to the frame. When the pistol is loaded the bronze lock is closed on the chambered round. When fired the bronze lock is held in place by the chamber pressure from the cartridge until the bullet leaves the barrel. At this point the pressure drops and, with the residual gas pressure, the bronze wedge is forced back and down the rails and the shell of the cartridge flies out the back and is deflected to the right by the pistol frame.

MODEL OF 1919, SERIAL NUMBER 7 - This Annihilator III, Model C, is the oldest American made submachine gun in private hands today. This Thompson was not designed to have either front or rear sights or buttstock. The actuator is offset to the right hand side of the gun. The actuator also serves as the gun’s firing pin mechanism. The bolt face is square in profile with a square chamber face. The rate of fire for this Thompson is in excess of 1500 rounds per minute, or 25 rounds per second. The firearm is only capable of firing in full automatic mode though burst firing is made possible through trigger control only.