In the early 19th century, Fort Osage which is also known as Fort Clark or Fort Sibley which was part of the United States factory trading post system for the Osage Nation. The Fort Osage was one of the three forts constructed by the U.S. Army for the purpose of gaining control over the newly acquired Louisiana Purchase territories. The Fort was officially named ?Fort Osage? by the man who was in charge of the military garrison in the name of Captain Eli Clemson. It has also been referred to as ?Fort Clark? in honor of William Clark who then was in charge of the Indian Affairs. The Fort Osage then was one of the First United States military installations in Louisiana and later on became a major stopping point for visitors.