The building of Fort Osage began in 1808 under the direction of William Clark (of Lewis and Clark fame). Built on a bluff overlooking the Missouri River, it was the western most outpost in the Louisiana Territory. The fort was used as a trading post for the Osage Indians and housed soldiers to guard the territory.
In the 1820s the fort was an important rendezvous point for the Santa Fe Trail traders. Major George C. Sibley was a trader and an Indian agent. In 1825, the United States government decided to survey the Santa Fe Trail marking it as the “Road to Santa Fe.”
Sibley was appointed as one of the commissioners for this project. The surveyors and commissioners started marking the Trail from Fort Osage. Many things went wrong with the survey, but the intention was to use compass directions and chains of specific lengths to mark the distance. They also built earth mounds along the Trail to mark the road for future travelers. The project didn’t produce the road that had originally been intended. By 1827, Fort Osage had been closed and the new fort across the Missouri, Fort Leavenworth, was opened.