[2] The township was named after Peter A. Karthaus, the proprietor of a local blast furnace.

There were 359 housing units at an average density of 10.1/sq mi (3.9/km2).

[5] There were 239 households, 25.5% had children under the age of 18 living with them, 51.5% were married couples living together, 8.4% had a female householder with no husband present, and 34.3% were non-families.

31.0% of households were made up of individuals, and 15.9% were one person aged 65 or older.

United Auto Workers organizer Wyndham Mortimer (1884–1966), First vice president of that union, from 1936 to 1939, and a key leader of the 1937 Flint Sit-Down Strike, was born in Karthaus.