Peterborough is a town in Hillsborough County, New Hampshire, United States. The population was 6,418 at the 2020 census. The main village, with 3,090 people at the 2020 census, is defined as the Peterborough census-designated place (CDP) and is located along the Contoocook River at the junction of U.S. Route 202 and New Hampshire Route 101. Peterborough is west of Manchester and northwest of Boston. History Granted by Massachusetts in 1737, it was first permanently settled in 1749. The town suffered several attacks during the French and Indian War. Nevertheless, by 1759, there were fifty families settled. Incorporated on January 17, 1760, by Governor Benning Wentworth, it was named after Lieutenant Peter Prescott (1709–1784) of Concord, Massachusetts, a prominent land speculator. The Contoocook River and Nubanusit Brook offered numerous sites for watermills, and Peterborough became a prosperous mill town. In 1810, the first cotton factory was established. By 1859, when the population was 2,222, there were four additional cotton factories, plus a woolen mill. Other industries included two paper mills, an iron foundry, a machine shop, a carriage factory, a basket manufacturer, a maker of trusses and supporters, a boot and shoe factory, seven sawmills, and three gristmills. Reverend Abiel Abbot, after being charged with heresy by the Connecticut religious establishment, came to Peterborough as minister to the Peterborough Unitarian Church in 1827. Reverend Abbot founded the town's first prep school, the Monadnock Summer Lyceum, and the first free library in the US, all in Peterborough. Peterborough established the first tax-supported free public library in the United States in 1833. Its success led the New Hampshire State Legislature to pass legislation in 1849 authorizing towns to raise money to establish and maintain their own libraries. The library was located in the town's general store and post office, and the postmaster served as librarian. The library moved to the town hall in 1873. Other early cultural institutions include Mariarden, a summer theatre where Paul Robeson played in Eugene O'Neill's The Emperor Jones at a time when roles for black Americans were scarce. Bette Davis performed there as a teen. Performance blossomed again in 1976, when Widdie and Jonathon Hall founded the Peterborough Folkway. "Within a few years, it became a 'must play' on the East Coast for folk musicians and continued to be a popular stop" for two decades. Regular performers included Tom Paxton, Mary Chapin Carpenter, Shawn Colvin, and Suzanne