In the fall of 1852, Captain Robert H. Chilton of the 1st U.S. Dragoons selected the junction of the Republican and Smoky Hill rivers as the site for a new military post. Surveyors named it Camp Center, believing it sat near the geographic center of the United States. The War Department approved the location in January 1853, and three companies of the 6th Infantry began construction that spring. The fort's first years coincided with the violent struggle over slavery in Kansas Territory. The first territorial legislature met at Fort Riley in July 1855, as pro-slavery and free-state factions tore the territory apart in the conflict known as Bleeding Kansas. The fort straddled the same fault line dividing the nation -- slavery was a fact of life within its garrison walls just as it was across the country. The seeds planted here would bloom into civil war within a decade.

The Civil War's end in 1865 brought Fort Riley a new mission: protecting the railroad lines being laid across the Kansas prairie. In the summer of 1866, the 7th Cavalry Regiment mustered in at the fort, and in December, Brevet Major General George Armstrong Custer arrived to take command. The flamboyant, controversial officer would drill his regiment at Riley before leading them into campaigns against the Southern Cheyenne on the southern plains. Custer's quarters at Fort Riley survive today as a historic house museum. The U.S. Cavalry Museum, housed in the building Custer used as his headquarters, traces the story of American mounted warfare from the Revolution to 1950. An M65 atomic cannon -- a Cold War relic capable of firing nuclear artillery shells -- sits in Freedom Park overlooking Marshall Army Airfield, a jarring juxtaposition of cavalry tradition and nuclear-age technology.

Fort Riley's modern identity is inseparable from the 1st Infantry Division, known as the Big Red One for its distinctive shoulder patch. The division was activated during World War I and has called Riley home at various points throughout its history. During World War II, approximately 125,000 soldiers trained at the fort's facilities. Among them were heavyweight boxing champion Joe Louis and movie star Mickey Rooney. President Franklin Roosevelt visited on Easter Sunday 1943. Jackie Robinson, who would break Major League Baseball's color barrier with the Brooklyn Dodgers in 1947, was once stationed at the fort, where he confronted the segregation of the Jim Crow-era military. The 1st Infantry Division deployed to Vietnam in 1965 and returned to Fort Riley in 2006, where it remains today as the post's primary tenant with two brigade combat teams, a division artillery, a combat aviation brigade, and a sustainment brigade.

Fort Riley's 101,733 acres span Geary and Riley counties in the Flint Hills of north-central Kansas, between the cities of Junction City and Manhattan. The Kansas River -- the Kaw -- runs along its northern boundary. The post encompasses six functional areas: Main Post, Camp Funston, Marshall Army Airfield, Camp Whitside, Camp Forsyth, and Custer Hill. The fort's legacy is not entirely heroic. Decades of improper waste disposal contaminated groundwater with pesticides, vinyl chloride, and volatile organic compounds, earning it Superfund status in 1990. But its human legacy extends in unexpected directions. The First Territorial Capitol of Kansas is preserved on post. Timothy McVeigh, who carried out the 1995 Oklahoma City bombing, was once stationed here. So was Robert K. Preston, who in 1974 stole a helicopter and landed it on the South Lawn of the White House. From cavalry charges to pandemic outbreaks, from Jackie Robinson to atomic cannons, Fort Riley has been an unlikely fulcrum of American history for over 170 years.