On June 23-24, 1804 the Corps of Volunteers for Northwestern Discovery spent Saturday afternoon, the night and early Sunday morning across the river from the bluffs which would, in four years time, become the site of Fort Osage. On September 8, 1808 General William Clark, now looking down those very bluffs, wrote in his journal "...this situation I had examined in the year 1804 and was delighted with it and am equally so now..."
In September 1806, the Corps concluded its mission with its return to St. Louis. March 1807 finds William Clark appointed as Indian Agent for the Territory. Clark returned to these bluffs, known as the rendezvoused with Captain Eli B. Clemson and his Company. George Sibley and Rueben Lewis and began the construction of Fort Osage. The government Indian Trade House was protected by Clemson's troops who were quartered in the Redoubt. This compound included four blockhouses, soldiers huts and officer's quarters with a fifth blockhouse located on the northern point of the bluff. The fortifications and adjacent buildings, gardens and cropland made this fort a veritable "Gibraltar of the Frontier."
Also, during September 1808, with the assistance of Nathan Boone, Daniel's so, Clark concluded a treaty with the Osage tribal leaders persuading them to cede much of their Missouri lands to the government on what Clark later admitted were shamefully inadequate terms.
(Continued on the other side)
At 9:00 in the morning on November 13, 1808, Capt. Clemson dedicated the fort in military fashion and named it "Fort Osage", so reported George Sibley the newly appointed government Factor at the Fort. In 1825, Sibley served as one of the three Commissioners on the U.S. Government Santa Fe Trail Survey.
With the Declaration of War with Britain in June of 1812, both the Military Garrison and the Indian trade operations were temporarily transferred away from the Fort. At the conclusion of the War in 1815, the Fort was re-garrisoned and the trade with the Indians reopened.
By 1822, all U.S. Government Indian Trade Houses were closed due to the pressure placed upon Congress by private fur companies. The Fort was finally closed in 1827 with the remaining lumber salvaged by area settlers for dwellings in the future town of Sibley and on local farms.
Fort Osage not only served as an important trading post for the Indians but also as an important early departure point for travelers and pioneers heading west. Later town replacements up river included first, Independence, then the "Town of Kansas" with newly established Fort Leavenworth nearby.