The first incarnation was humble. Camp on Pawnee Fork became Camp Alert in 1860 -- a name earned by its garrison of fifty men who had to remain perpetually vigilant. Moved thirty miles west up the Pawnee Fork in May 1860, it was renamed Fort Larned by month's end. The original structures were poorly built from adobe bricks: an officer's quarters, two combination storehouses and barracks, a guardhouse, two laundresses' quarters, and a hospital, with a bakery and meat house added later. The fort served double duty as a Bureau of Indian Affairs agency under the Fort Wise Treaty of 1861, administering the Central Plains Indians. For a time, the relationship held. In August 1861, Colonel Leavenworth reported from Fort Larned that the Indians had left the Santa Fe Trail area and there was no apprehension of hostilities.

The Civil War changed everything. Regular Army troops were pulled east to fight the Confederacy, replaced by volunteer units from Kansas, Colorado, and Wisconsin who lacked the frontier experience of their predecessors. Raids and harassment of travelers by Plains Indians escalated sharply. On July 17, 1864, Kiowa warriors executed a bold stroke: they raided Fort Larned itself and stole 172 horses and mules from the corral. The raiders were pursued but never caught. By 1865, no merchant was permitted to travel westward beyond Fort Larned without an armed escort. The Confederacy even reached for the fort indirectly. In May 1862, Confederate General Albert Pike arranged an alliance with Kiowa and Seminole Indians to capture Forts Larned and Wise. The plan dissolved when the Indians departed for their annual hunt as the weather improved -- seasonal rhythms trumping military strategy.

On April 12, 1867, General Winfield Scott Hancock arrived at Fort Larned to meet Cheyenne Dog Soldier chiefs. Hancock intended to impress them with military power. After the meeting, Hancock marched west with George Armstrong Custer and the 7th U.S. Cavalry to a combined Cheyenne and Lakota camp. The villagers, seeing the approaching column, fled. Hancock ordered the village burned. That act ignited a summer of warfare known as Hancock's War. Fort Larned then played a role in ending the conflict it had helped provoke, supplying the Medicine Lodge Treaty negotiations. During the winter of 1868-69, Major General Philip Sheridan launched his winter campaign against the Cheyenne, Kiowa, and Comanche from the region, attacking those who resisted and forcing the remaining Indians onto reservations.

Among the twenty-four units stationed at Fort Larned during its nineteen years of operation, the 10th U.S. Cavalry holds a singular place. Stationed from 1867 to 1869, the 10th was one of the first two all-black cavalry regiments in the United States. These Buffalo Soldiers served on the frontier under conditions that combined racial hostility from fellow soldiers with the physical dangers of plains warfare. On January 2, 1869, the 10th Cavalry's stables at Fort Larned burned to the ground. The fire killed dozens of horses, destroyed equipment, and forced the unit's reassignment to Fort Zarah. In 1999, archaeologists used magnetic gradiometry and electromagnetic conductivity surveys to locate the lost stables, finding buried anomalies consistent with building foundations beneath the Kansas soil.

Between 1866 and 1868, the original adobe structures were replaced with the sandstone buildings that survive today. By 1871, wagon trains no longer required armed escorts on the Santa Fe Trail, and the fort's reason for existing evaporated. The post was abandoned on July 13, 1878. In 1883, the military reservation was transferred to the Department of the Interior. From 1885 to 1966, a ranching family made the fort their home -- the owners living in the commanding officer's quarters, employees in what had been the officers' billets. That agricultural second life likely preserved the buildings that might otherwise have been quarried for stone. Today, operated by the National Park Service as Fort Larned National Historic Site, the fort stands as one of the best-preserved examples of a frontier military post in the American West.