The township is named after Sarah Sabina Cooper, the wife of Horace H. Comstock, an early pioneer of the area and founder of nearby Comstock.

As of the census[1] of 2000, there were 8,754 people, 3,187 households, and 2,489 families residing in the township.

There were 3,269 housing units at an average density of 90.1 per square mile (34.8/km2).

The racial makeup of the township was 96.16% White, 1.36% African American, 0.30% Native American, 0.45% Asian, 0.01% Pacific Islander, 0.39% from other races, and 1.34% from two or more races.

17.9% of all households were made up of individuals, and 7.2% had someone living alone who was 65 years of age or older.