A cannonball from the period remains lodged in the side of the Friends Meeting House. According to the United States Census Bureau, the township had a total area of 21.52 square miles (55.735 km2), including 21.334 square miles (55.254 km2) of land and 0.186 square miles (0.481 km2) of water (0.86%),  Municipalities bordering the township are Bordentown Township, Mansfield Township, North Hanover Township, Springfield Township in Burlington County; and Hamilton Township in Mercer County. Unincorporated communities, localities and place names located partially or completely within the township include Crosswicks, Davisville and Extonville. The census statistics above include residents of a state youth detention center located at the northwest edge of Chesterfield Township, on the border with Hamilton Township. The Census Bureau's 2006-2010 American Community Survey showed that (in 2010 inflation-adjusted dollars) median household income was $113,125 (with a margin of error of +/- $10,124) and the median family income was $120,288 (+/- $8,240). Males had a median income of $76,563 (+/- $13,303) versus $58,229 (+/- $12,489) for females. The per capita income for the borough was $20,655 (+/- $4,105). About none of families and 0.9% of the population were below the poverty line, including none of those under age 18 and 2.0% of those age 65 or over. As of the 2000 United States Census there were 5,955 people, 899 households, and 744 families residing in the township. The population density was 278.1 people per square mile (107.4/km²). There were 924 housing units at an average density of 43.1 per square mile (16.7/km²). The racial makeup of the township was 49.71% White, 37.36% African American, 0.67% Native American, 0.64% Asian, 0.08% Pacific Islander, 8.45% from other races, and 3.09% from two or more races. Hispanic or Latino of any race were 12.34% of the population. The census statistics above included 3,341 residents of state correctional facilities located in the township. There were 899 households out of which 38.8% had children under the age of 18 living with them, 72.6% were married couples living together, 6.3% had a female householder with no husband present, and 17.2% were non-families. 12.8% of all households were made up of individuals and 4.8% had someone living alone who was 65 years of age or older.