 Stephen A. Douglas ( D ) , the chair of the United States Senate Committee on Territories , drafted the bill authorizing the Minnesota Territory in 1848 . He had envisioned a future for the upper Mississippi valley , so he was motivated to keep the area from being carved up by neighboring territories . In 1846 , he had prevented Iowa from including Fort Snelling and Saint Anthony Falls within its northern border . In 1847 , he kept the organizers of Wisconsin from including Saint Paul and Saint Anthony Falls . The Minnesota Territory was established from the lands remaining from Iowa Territory and Wisconsin Territory on March 3 , 1849 . The Minnesota Territory extended far into what is now North Dakota and South Dakota , to the Missouri River . There was a dispute over the shape of the state to be carved out of Minnesota Territory . An alternate proposal that was only narrowly defeated would have made the 46th parallel the state 's northern border and the Missouri River its western border , thus giving up the whole northern half of the state in exchange for the eastern half of what later became South Dakota . 
