Fort Collins was founded as a military outpost of the United States Army in 1864. A previous encampment, known as Camp Collins, on the Cache La Poudre River near present-day Laporte, was destroyed by a flood in June 1864. Afterwards, the commander of the fort wrote to Colonel William O. Collins at Fort Laramie in southeast Wyoming, suggesting that a site several miles further down the Poudre would make a good location for the fort. The fort never had walls.

     Settlers began arriving in the vicinity of the fort nearly immediately. The fort was decommissioned in 1868 and the original fort site is now adjacent to the present historic "Old Town" portion of the city. The town was formally incorporated in 1873. Stone quarrying, sugar beet farming, and sheep were among the areas's earliest industries. Fort Collins is home to Colorado State University, Colorado's original land-grant college (formerly known as Colorado Agricultural and Mechanical College). Other large employers include Hewlett-Packard, Poudre Valley Health System, and Poudre School District.