The land purchased contained all of present-day Arkansas , Missouri , Iowa , Oklahoma , Kansas , and Nebraska ; parts of Minnesota that were west of the Mississippi River ; most of North Dakota ; most of South Dakota ; northeastern New Mexico ; northern Texas ; the portions of Montana , Wyoming , and Colorado east of the Continental Divide ; Louisiana west of the Mississippi River, including the city of New Orleans ; and small portions of land that would eventually become part of the Canadian provinces of Alberta and Saskatchewan .