The military post of Fort King, the site of which is within the present city limits of Ocala, was built as housing for soldiers and government agents prior to the Second Seminole War of Florida (1835-1842). Additionally, the fort site would function as a community center, and the services of a sutler's store and blacksmith were available to nearby settlers. Traders and civilian craftsmen in service to the military and local populace built small, one-story cabins around the fort. The large fort and stockade served a protective function for nearby settlers in the event of an attack by the Seminole Indians.

Fort King was established in 1827 in response to an escalation of conflicts between white settlers and traders and the Seminole. The situation in north central Florida became increasingly tense beginning in the early 1820s, when emigrants from the southeastern United States began flocking to the promising frontier lands of the Florida Territory. The federal land office was opened in Tallahassee in 1825. The wealth of the territory was based prospectively upon the soils of the land that could support agricultural enterprises. Most land speculators vied for the rich highlands of the interior north-central region.

At this time, an estimated 5,000 Seminole resided in the prime lands between the Apalachicola River and the port of St. Augustine. Competition for land and resources of the area led to hostile actions and reactions between Indians and settlers. The latter demanded action by the federal government for protection of person and property.

In order to enforce the various acts passed by the territorial and United States government concerning the Seminoles and buffer hostilities between whites and Seminole, a military post to be known as Camp King was designed to be placed on the southern frontier of the Alachua, and near the northern boundary of the Moultrie Creek Treaty reservation boundary. Two companies from Fort Brooke (Tampa) under the command of Captain James Glassell were directed by Colonel Clinch to erect a fort in the vicinity of the Ocklawaha River, a mile west of the Indian Agency. This Indian Agency was previously established by agent Gad Humphreys at Silver Springs. In the last week of March 1827, the construction of Camp King began atop a small hill situated near a spring and creek. The area was heavily wooded. The camp and fort were to be titled Cantonment King after Colonel William King, commander of the Fourth Infantry of Florida.

A stockade was erected, enclosed by a barricade of split logs that stood 20 feet tall. A blockhouse was constructed on one corner. Other buildings enclosed two kitchens and quarters for enlisted men and officers, and storage buildings. The stockade enclosed an area 162 by 152 feet. The fort was occupied by troops on and off for the next 17 years.