Union Grove Township was settled in 1856 by Lyman Allen, Andrew Hamilton, John Lowell Haywood, and a man named Baker.

Baker died in Union Grove for unknown reasons.

These residents also found the necessity to rule that hogs and sheep could not run loose between April 1 and November 1.

During and following the US-Dakota War of 1862, several of the early families left the area and never returned.

20.4% of all households were made up of individuals, and 8.7% had someone living alone who was 65 years of age or older.

About 2.2% of families and 3.6% of the population were below the poverty line, including 5.6% of those under the age of 18 and none of those 65 and older.