Hudson is a town in Hillsborough County, New Hampshire, United States. It is located along the Massachusetts state line. The population was 25,394 at the 2020 census. It is the tenth-largest municipality (town or city) in the state, by population. The urban center of town, where 7,534 people resided as of the 2020 census, is defined as the Hudson census-designated place (CDP) and is located at the junctions of New Hampshire routes 102, 111 and 3A, directly across the Merrimack River from the city of Nashua. History Hudson began as part of the Dunstable Land Grant that encompassed the current city of Nashua, New Hampshire, and the towns of Dunstable and Pepperell, Massachusetts, as well as parts of other nearby towns on both sides of the border. In 1732, all of Dunstable east of the Merrimack River became the town of Nottingham, Massachusetts. Nine years later, the northern boundary of Massachusetts was finally officially established, and the New Hampshire portion of Nottingham became Nottingham West, to avoid confusion with Nottingham, New Hampshire, to the northeast. In 1830, after the better part of a century, the name was changed to "Hudson" to avoid confusion with the older town of Nottingham. The name apparently comes from an early belief that the Merrimack River had once been thought to be a tributary of the Hudson River, or that the area had once been explored by Henry Hudson; both proved to be entirely apocryphal stories, but the name of the town remains today. A prominent family in Hudson history was the Alfred and Virginia Hills family, who owned a large tract of land north of Hudson Village. Dr. Hills' ancestors were original settlers of Hudson. The Hills House on Derry Road (now listed on the National Register of Historic Places) is the original family's vacation home and current location of the Hudson Historical Society. The grounds host the annual "Old Home Days" fair every year as well as "Harvest Fest" and the "Bronco Belly Bustin' Chili Fiesta", an Alvirne High School Friends of Music fundraiser. Hills Memorial Library (also listed on the National Register) is one of the oldest public lending libraries in the state, and occupies a stone and mortar building on Library Street. Alvirne High School and the Alvirne Chapel, located on family land across Derry Road from the Hills House, were donated to the town. ("Alvirne" is a contraction of "Alfred"