Charlestown is a town in Sullivan County, New Hampshire, United States. The population was 5,114 at the 2010 census. The town is home to Hubbard State Forest and the headquarters of the Student Conservation Association.
Charlestown is located along the Connecticut River, the western border of New Hampshire.
According to the United States Census Bureau, the town has a total area of 38.0 square miles (98.5 km), of which 35.8 sq mi (92.7 km) is land and 2.2 sq mi (5.8 km) is water, comprising 5.90% of the town. Charlestown is drained by Clay Brook. The highest point in town is Sams Hill, at 1,683 feet (513 m) above sea level). Charlestown lies fully within the Connecticut River watershed.
In the Connecticut River in the 1800s were three islands within the limits of the town. Sartwell’s Island, the largest, containing 10 acres (4.0 ha), was under a high cultivation in 1874. The others contained about 6 acres (2.4 ha) each. None show on maps today, and were presumably inundated by the power dam built downstream at Bellows Falls.
As of the census of 2010, there were 5,114 people, 2,117 households, and 1,399 families residing in the town. There were 2,263 housing units, of which 146, or 6.5%, were vacant. The racial makeup of the town was 97.8% white, 0.4% African American, 0.2% Native American, 0.4% Asian, 0.0% Native Hawaiian or Pacific Islander, 0.1% some other race, and 1.0% from two or more races. 0.8% of the population were Hispanic or Latino of any race.
Of the 2,117 households, 28.8% had children under the age of 18 living with them, 50.4% were headed by married couples living together, 10.0% had a female householder with no husband present, and 33.9% were non-families. 27.4% of all households were made up of individuals, and 11.3% were someone living alone who was 65 years of age or older. The average household size was 2.38, and the average family size was 2.84.
In the town, 20.7% of the population were under the age of 18, 7.7% were from 18 to 24, 23.3% from 25 to 44, 32.4% from 45 to 64, and 16.2% were 65 years of age or older. The median age was 43.9 years. For every 100 females, there were 97.2 males. For every 100 females age 18 and over, there were 94.4 males.
For the period 2011-2015, the estimated median annual income for a household was $41,471, and the median income for a family was $52,708. The per capita income for the town was $23,527. 13.2% of the population and 9.5% of families were below the poverty line. 16.0% of the population under the age of 18 and 9.1% of those 65 or older were living in poverty.