Cosmos, Minnesota was incorporated on September 26, 1926.  The first mayor was Arthur W. Johnson.  Ernest Grussendorf, J.M. Lietzau and Albert Anderson were the promoters for incorporating the village. 

The original townsite consisted of four blocks and undivided Out Lot C.  The plat was filed January 31, 1923 and the survey was made by Sven A Vaule.  The town was laid out by Harry Hart, August 29, 1923 and the engineer was T.S. Herverdine of Olivia. 

When Cosmos was laid out, plans were made for the beautiful wide main street that Cosmos is known for. 

The original townsite was increased by the following additions: Larson's First, Anderson's Addition, and rearrangements of Out Lot A, Lietzau's First, Lietzau's Summit, Nelson's First, and Nelson's subdivision of Section 21.