Early Utah military history includes events such as the Utah War and the Spanish American War. Major early installations included Camp Floyd (1858-1861) and Camp Douglas (est. 1862).

Camp Floyd (1858-1861), named for Secretary of War, John B. Floyd, housed the largest concentration of U. S. troops to that time, in what immediately became the third largest city in Utah. The camp was a product of the "Utah War" when President Buchanan sent federal troops to the Utah territory in 1857.

The army at Camp Floyd found itself isolated. It organized its own theatrical productions, a circus, a temperance society, a Masonic lodge, engineered a unique watering system, planted gardens, and regularly honed their military skills through drills and instruction. They also assisted in improving western immigrant roads. Under the direction of Captain James H. Simpson of the Army Corps of Engineers, new routes were mapped which shortened travel time between the states and California and already existing trails were improved. Scientists and artists accompanying the troops studied the scenery as well as the plant life and wild life.

In 1860, Floyd was dismissed from cabinet for his Southern sympathies, the post was renamed Fort Crittenden. When fighting in the South escalated into the Civil War, the troops were called East to that conflict. By midsummer of 1861 Camp Floyd/Fort Crittenden was abandoned.

Fort Douglas was established on October 26, 1862, by Colonel Patrick E. Connor and the California Volunteers during the American Civil War. Originally named Camp Douglas (after Senator Stephen A. Douglas), the post was renamed Fort Douglas in 1878. In the late 19th century, several African-American regiments (Buffalo Soldiers), including the 24th Infantry, were stationed at the fort and trained there before departing for the Spanish-American War.

During World War I the fort served as a training base and an internment camp for German POWs and German-American civilians.

The Spanish-American War (April 21-August 13, 1898) was a conflict between the United States and Spain. It originated in the Cuban War of Independence from Spanish colonial rule (1895-1898), which was the last of three Cuban wars for liberation. The United States intervened in the war after the sank in the harbor of Cuba, Havana. The war caused Spain's withdrawal from its colonial presence in the Americas and resulted in United States acquisition of territories in the Caribbean and Pacific regions, including Puerto Rico and Guam.

Like other states, Utah became involved in the war when the federal government called for 125,000 volunteers to join the small regular army of the United States. Utah's original quota of volunteers was 425, but by the end of the conflict Utah had sent 800 troops, mostly sourced from the Utah National Guard. Upon the return of these troops, Governor Heber Wells proclaimed August 19, 1898 a holiday. A special "arch of triumph" was placed at 200 South and Main streets in Salt Lake City; a parade, with almost all of the volunteers represented, marched through Salt Lake City; and festivities and speeches at Liberty Park honored the soldiers.

The Utah National Guard was officially organized on March 26, 1894, in Salt Lake City, Utah, when the first two companies of infantry and the first battery of artillery were formed.

Trouble along the Mexican border caused President Woodrow Wilson to activate the National Guard in 1916, sending artillery, cavalry, and hospital corps to patrol the border. Some of these troops were still in federal service when Congress declared war on Germany, April 6, 1917. Nearly 1,400 Utah Guard members were involved in World War I.

Today, Utah has a robust military presence, driven by Hill Air Force Base—the state's largest employer. Key installations include the Utah Test and Training Range (UTTR), Dugway Proving Ground, The Toole Army Depot, and Camp Williams.