The land of Marshall Township originally contained a few small, shallow lakes, but they have since been drained to allow for increased farming.

a Norwegian, settled in the western half of the southwest quadrant of section 36 in 1856 and John Osmunsen (born Jone Hauske Osmundson), another Norwegian, came from Wisconsin and settled in the eastern half of the southeast quadrant of the same section the following year together with his wife Ellen Serena Osmundsen (born Vignes, Hansdatter / daughter of Hans and Siri Olsen Finnøy, Norway).

At the organizing meeting of June 6, 1870, the people of the township elected two supervisors, a chairman, a clerk, an assessor, a treasurer two justices of the peace and two constables.

According to the United States Census Bureau, the township has a total area of 34.6 square miles (89.6 km2), all land.

The racial makeup of the township was: two Native Americans, and two Asians, and the rest of the people are white.