Mount Pleasant Township was organized in 1858, and so named on account of the scenic overlooks from area summits.

[4] According to the United States Census Bureau, the township has a total area of 36.0 square miles (93.2 km2), all of it land.

The township contains two properties listed on the National Register of Historic Places: the 1858 Lake City and Rochester Stage Road–Mount Pleasant Section and the 1880 Patrick H. Rahilly House.

The racial makeup of the township was 98.95% White, 0.21% Native American, 0.63% Asian, 0.21% from other races.

13.7% of all households were made up of individuals, and 4.6% had someone living alone who was 65 years of age or older.