[2] To protect Butterfield Overland Despatch stage and freight wagons traveling the Smoky Hill Trail from Cheyenne and Arapaho attacks, the U.S. Army established Fort Fletcher on October 11, 1865.

This time, the purpose of the fort was to protect workers building the Union Pacific Eastern Division railway westward, parallel to the Smoky Hill Trail.

[2][3] The Army planned to use Fort Hays as a supply depot for other posts in the region and thus needed it to be located close to the railway.

[2] On orders from Maj. Gen. Winfield Hancock, Maj. Alfred Gibbs chose a new location 15 miles (24.1 km) to the northwest where the railway would cross Big Creek.

The post was designed as a base for supplies and troops who could be dispatched into the field to protect vulnerable people and places when conflict with Plains Indians broke out.

Buried at the base of a nearby hill, she went on to become a figure in local folklore, the "Blue Light Lady," as people claimed to see her ghost in the area around the fort.

Miles led the 5th Infantry Regiment, assigned to protect the railroad as its construction extended west into Colorado Territory.

The Kansas Legislature requested that the site be donated for use as a soldiers' home, but the U.S. Department of the Interior (DOI) subsequently assumed custody of the fort's land and buildings.

The site includes a visitor center, the fort's parade ground, and four of its original buildings: the blockhouse, the guardhouse, and two of the officers' quarters.

[19] Commemorating the 1867-1967 centennial, the sculpture Monarch of the Plains was installed overlooking the highway passing the Historic Site.

[20] It consists of 177 acres (72 ha) on the south side of the U.S. Route 183 Bypass immediately southwest of Hays, Kansas.

The main campus of Fort Hays State University lies north of the site across the bypass and Big Creek.