 In 1805 U.S. Lieutenant <unk> Pike was sent by General Wilkinson , governor of the Louisiana Territory , to enforce U.S. sovereignty against British traders in the area and establish diplomatic and trading relationships with the native tribes . He met with the Sioux leadership in central Minnesota to secure rights for the U.S. to an area near Saint Anthony Falls , which would later become the city of Saint Paul . Though a treaty was signed by some leaders from the Sioux tribes , its legitimacy ( including whether the Sioux understood it ) was dubious and ultimately his efforts did little to establish the authority of the U.S. in the area . 
