[3] The township was organized in 1839, named for the site of the Battle of Marathon in ancient Greece.

As of the census[1] of 2000, there were 4,701 people, 1,617 households, and 1,301 families residing in the township.

There were 1,764 housing units at an average density of 52.8 per square mile (20.4/km2).

There were 1,617 households, out of which 39.1% had children under the age of 18 living with them, 66.9% were married couples living together, 8.7% had a female householder with no husband present, and 19.5% were non-families.

15.7% of all households were made up of individuals, and 5.6% had someone living alone who was 65 years of age or older.