The Ithaca 37 is based on a 1915 patent by the famous firearms designer John Browning, initially marketed as the Remington Model 17. The Model 17 was a 20-gauge of trim proportions, which Remington later redesigned and refined into the popular side-ejecting Remington Model 31. The Model 31 would eventually be replaced in production by the less expensive to make Remington 870 which is still produced to this day.
Following the First World War, the Ithaca Gun Company was searching for a pump-action shotgun to produce, primarily to compete with the ubiquitous Winchester Model 1912. They settled on waiting for Remington Model 17 patents to expire. After gearing for production of the Ithaca Model 33, they discovered a Pedersen patent that would not expire until 1937; along with the introduction date, they changed the model designation from 33 to 37.
With the depression dragging on and war looming on the horizon, it was possibly the worst time to introduce a sporting arm. Many sporting arms ceased production entirely during the same period. While Ithaca did produce some shotguns for military use during the war, they also produced M1911 pistols and M3 Grease Guns.
After WW-II, Ithaca resumed production of the Model 37. Made in many different models, the Ithaca 37 has the longest production run for a pump-action shotgun in history, surpassing that of the Winchester Model 12 that had originally inspired Ithaca to produce pump-action shotguns. Ithaca has suffered many setbacks in its history, changing hands numerous times. At one time, the Ithaca 37 was renamed the Model 87, although it was soon changed back in one of many ownership changes. Production paused in 2005 when Ithaca once again changed hands. Production has resumed in Ohio.