Mansfield Township is a township in Warren County, New Jersey, United States. As of the United States 2000 Census, the township population was 6,653. The township was created in 1754 out of Greenwich Township and was named after William Murray, 1st Earl of Mansfield. The township is part of the eastern region of the Lehigh Valley.
Mansfield Township was formed from portions of Greenwich Township, while the area was still part of Sussex County, and was incorporated as one of New Jersey's initial group of 104 townships by an Act of the New Jersey Legislature on February 21, 1798. Mansfield Township became part of the newly-formed Warren County on November 20, 1824. Portions of the township were taken to form Franklin Township (April 8, 1839) and Washington Township (April 9, 1849).
There were 2,334 households out of which 39.0% had children under the age of 18 living with them, 61.3% were married couples living together, 9.0% had a female householder with no husband present, and 25.0% were non-families. 18.9% of all households were made up of individuals and 6.3% had someone living alone who was 65 years of age or older. The average household size was 2.76 and the average family size was 3.18.
In the township the population was spread out with 27.0% under the age of 18, 6.2% from 18 to 24, 32.4% from 25 to 44, 22.7% from 45 to 64, and 11.7% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 94.8 males. For every 100 females age 18 and over, there were 91.2 males.
The median income for a household in the township was $61,763, and the median income for a family was $76,102. Males had a median income of $50,295 versus $35,737 for females. The per capita income for the township was $26,277. About 2.7% of families and 3.9% of the population were below the poverty line, including 3.9% of those under age 18 and 5.9% of those age 65 or over.
Members of the Mansfield Township Committee are Mayor Ellen Nerbak (R, term ends December 31, 2008), Deputy Mayor George Baldwin (R, 2010), Robert Jewell (R, 2010), Cate Oakley (R, 2008) and Joseph Watters (R, 2009).
Public school students in grades 7 and up attend the schools of the Warren Hills Regional School District. Warren Hills is a Grade 7-12 district in Warren County that serves approximately 2,100 students from the municipalities of Washington Borough, Washington Township, Mansfield Township, Franklin Township and Oxford Township (for 9-12 only).
A small general aviation airport, named Hackettstown Airport and holding the official database designation of is in Mansfield Township, only a few hundred yards from the municipal border with Hackettstown proper.