Pelham is a town in Hillsborough County, New Hampshire, United States. The population was 12,897 at the 2010 census, and in 2017 the estimated population was 13,681.Pelham was split from Old Dunstable in 1741, when the border between Massachusetts and New Hampshire was settled. It was incorporated in 1746. The town is named after Thomas Pelham-Holles, 1st Duke of Newcastle.According to the United States Census Bureau, the town has a total area of 26.9 square miles (69.8 km2), of which 26.4 square miles (68.3 km2) are land and 0.58 square miles (1.5 km2), or 2.09%, are water. The highest point in Pelham is Jeremy Hill, at 577 feet (176 m) above sea level.
The town contains the southernmost point in the state of New Hampshire, at 42°41′49″N 71°17′40″W, a location known as the “Old Boundary Pine”, named for a pine tree that marked the difference in definition of the northern boundary of Massachusetts. This point is 3 miles (5 km) due north of Pawtucket Falls in Lowell, and marks the point where the straight-line border to the west meets the 3-mile buffer defined by the Merrimack River.In addition to being New Hampshire’s southernmost town, Pelham is the easternmost town in Hillsborough County.
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