Merrimack is a town in Hillsborough County, New Hampshire, United States. The population was 25,494 at the 2010 census, and an estimated 25,660 in 2017, making it the ninth-largest municipality in New Hampshire.
There are four villages in the town: Merrimack Village (formerly known as Souhegan Village), Thorntons Ferry, Reeds Ferry, and South Merrimack.
The first known settlers of the area appeared sometime after the last ice age. Merrimack is a Native American term meaning sturgeon, a type of fish. The Pennacook people named the Merrimack River after this fish because of the vast population that once existed there. The Penacooks spelled it Monnomoke or Merramake. "When the town was incorporated, it took the name of the river and spelled it Merrymac," according to the Merrimack Historical Society.
The first mention of the territory containing the current town of Merrimack among written records was the petition of Passaconaway to the General Court of Massachusetts for a grant of land to include a part of this region. This was in 1662, and in the autumn of that year the court acceded to the request, and the aged sachem and his associates were granted a strip of country a mile and a half wide on both banks of the Merrimack at this section of the river. Although the boundaries of this grant are not specifically known today, it is probable that the chieftain held at least a portion of the current town of Merrimack. European settlers first came to the area in the late 17th century when the area was still in dispute between the Province of New Hampshire and Massachusetts Bay Colony.