Ithaca based the Model 37s off of John Browning and John Pedersen’s design for the Remington Model 17. Like the Model 17, the Model 37 is a pump-action shotgun that ejects spent casings from the bottom of the receiver rather than the side, as most shotguns do.
The gun went into production in 1937 and -except for a few brief instances- has remained in production ever since. Ithaca originally began producing the gun to compete with the popular Winchester Model 1912, which John Browning, the noted gun developer, also helped design.
Browning’s designs for the Model 17 would eventually yield the Remington 17 and ultimately the Remington 870. Thus, the Remington 870 and Ithaca Model 37 stem from the same basic design and remain somewhat comparable. Law enforcement and sportsman alike have favored the Model 37 for its reliability and ambidextrous design.
The bottom eject originated from the thought that debris and the elements would be less apt to interfere with the gun’s action if the eject wasn’t housed on the side of the weapon.
Though introduced before the Word War II, the gun wouldn’t see widespread manufacturing and distribution until after the war. During the war, Ithaca primarily produced M1911 pistols and M3 submachine guns, as the domestic demand for sporting shotguns remained minimal at the time and government contracts sizable.
After the war concluded in 1945, the company again revamped the production of the Model 37 and the gun saw larger distribution and sales, eventually becoming the company’s most recognized firearm. The Ithaca Gun Company has been bought several times, but the company still sells new Model 37s.