 Most of the remaining areas of what is now the state were purchased in 1803 from France as part of the Louisiana Purchase ( the area west of the Mississippi having been recently acquired by France from Spain ) . Parts of northern Minnesota were considered to be in Rupert 's Land , a large territory owned by Hudson 's Bay Company . The exact definition of the boundary between Minnesota and British North America was not addressed until the Anglo @-@ American Convention of 1818 . 
