 After the Civil War , Minnesota became an attractive region for European immigration and settlement as farmland . Minnesota 's population in 1870 was 439 @,@ 000 ; this number tripled during the two subsequent decades . The Homestead Act in 1862 facilitated land claims by settlers , who regarded the land as being cheap and fertile . The railroad industry , led by the Northern Pacific Railway and Saint Paul and Pacific Railroad , advertised the many opportunities in the state and worked to get immigrants to settle in Minnesota . James J. Hill , in particular , was instrumental in reorganizing the Saint Paul and Pacific Railroad and extending lines from the Minneapolis @-@ Saint Paul area into the Red River Valley and to Winnipeg . Hill was also responsible for building a new passenger depot in Minneapolis , served by the landmark Stone Arch Bridge which was completed in 1883 . During the 1880s , Hill continued building tracks through North Dakota and Montana . In 1890 , the railroad , now known as the Great Northern Railway , started building tracks through the mountains west to Seattle . Other railroads , such as the Lake Superior and Mississippi Railroad and the Milwaukee Road , also played an important role in the early days of Minnesota 's statehood . Later railways , such as the Soo Line and Minneapolis and St. Louis Railway facilitated the sale of Minneapolis flour and other products , although they were not as involved in attracting settlers . 
