Agricultural expansion and the establishment of Willmar as a division point on the Great Northern Railway
determined the growth of the community. The first settlers arrived during the 1850s, attracted to the fertile land and an abundance of timber and game. The Dakota War of 1862
left the township abandoned for several years. The advent of the railroad in Kandiyohi County in 1869 brought new settlers. Many were of Swedish and Norwegian origins; residents of Scandinavian
heritage are still a majority. In 1870, Leon (Chadwick) Willmar, a Belgian acting as an agent for the European bondholder of the St. Paul and Pacific Railroad
, purchased the title to Section 1 of Willmar Township.
Willmar was established as the county seat in 1871 and was incorporated as a village in 1874 and as a city in 1901