Oscar Frederick Mossberg (1866–1937) was born on 1 September 1866, in Sweden, near the village of Svanskog in Värmland, and emigrated to the United States in 1886.

[3][5] When Mossberg left Iver Johnson, he went on to manage the small factory of the C. S. Shattuck Arms Co. in nearby Hatfield, Massachusetts, which manufactured single- and double-barrel breechloading shotguns.

[3] Renting a small loft on State Street in New Haven, the Mossbergs began work on a simple four-shot .22-caliber pocket pistol, the Brownie.

[3] Marketed largely to hunters and trappers for the humane killing of wounded or trapped animals, Mossberg produced approximately 37,000 Brownie pistols from 1920 to 1932.

[3] Thanks to the Brownie pistol, the Mossbergs' firearms business grew steadily, and in 1921 the company purchased a building on Greene Street in New Haven, Connecticut.

In 1989, faced with increased foreign competition and rising labor and production costs, Mossberg's corporate affiliate Maverick Arms opened a 40,000-square-foot (3,700 m2) manufacturing plant in the Eagle Pass Industrial Park in the state of Texas.

[2][9][10] After the end of World War II, Mossberg concentrated on producing sporting long guns for entry-level shooters, mainly shotguns.