Hillsborough, frequently spelled Hillsboro, is a town in Hillsborough County, New Hampshire, United States. The population was 5,939 at the 2020 census. The town is home to Fox State Forest and part of Low State Forest. The main village of the town, where 2,156 people resided at the 2020 census, is defined as the Hillsborough census-designated place (CDP), and is located along the Contoocook River at the junction of New Hampshire Route 149 with Henniker Street and Main Street. The town also includes the villages of Hillsborough Center, Hillsborough Upper Village, Hillsborough Lower Village, and Emerald Lake Village. History The town was first granted in 1735 by Jonathan Belcher, colonial governor of Massachusetts and New Hampshire, as "Number Seven", one in a line of nine Massachusetts towns set up as defense barriers against Indian attacks. The towns were renamed after the border between the two provinces was fixed in 1739, placing the towns in New Hampshire. Settled in 1741, the town was granted in 1748 by Governor Benning Wentworth as "Hillsborough", named for Sir Wills Hill, Earl of Hillsborough. It would be incorporated in 1772 by Governor John Wentworth. Hillsborough was the birthplace of Franklin Pierce, the 14th president of the United States and the only president from New Hampshire. The Pierce Homestead was built in 1804 (the year of his birth) by his father, Benjamin Pierce, a general in the Revolutionary War, and twice governor of New Hampshire. Restored in 1925, the home was designated a National Historic Landmark in 1961. Listed on the National Register of Historic Places, the house is today a museum owned by the state and operated by the Hillsborough Historical Society. A cluster of five stone arch bridges built during the 19th century in Hillsborough is designated as a National Historic Civil Engineering Landmark. Railroad service was supplied to Hillsborough by the Boston and Maine Railroad from 1878 to 1972. Rail service north to Henniker ceased in 1942, and Hillsborough became the end point on a line that once stretched in an arc from Nashua to Concord, New Hampshire. The rails in Hillsborough were torn up in 1979. Hillsborough was once home to an iconic railroad covered bridge and a curved wooden trestle. The bridge burned due to arson in 1985, and the trestle was dismantled shortly thereafter. The Hillsborough Branch now ends at Bennington; the line from Bennington to Hillsborough is a rail