 At the outset of the 19th century most of the European settlements were related to the fur trade . The largest of these settlements were trading posts established by the North West Company , particularly those at Sandy Lake , <unk> Lake , and Fond du Lac . Historian Grace Lee <unk> has documented over 100 fur trading posts of varying sizes in the Minnesota area before statehood . Most of these posts were eventually taken over by the American Fur Company . When several hundred settlers abandoned the Red River Colony in the 1820s , they entered the United States by way of the Red River Valley , instead of moving to eastern Canada or returning to Europe , adding to the Minnesota region 's population . 
