Brentwood is a town in Rockingham County, New Hampshire, United States. As of the 2010 census, its population was 4,486. Brentwood has been the county seat of Rockingham County since 1997. An Abenaki tribe called the Pennacook farmed, fished and hunted in what is now Brentwood. Two main foot trails ran through the town, one along the Exeter River, where arrowheads and other stone and wooden artifacts have been found. At Pickpocket Dam, this pathway joined with the Pentucket Trail leading south to Pentucket (now Haverhill, Massachusetts) and north further into Pennacook territory. The first non-native settlers came in 1652 to start a sawmill powered by a waterfall on the Exeter River.
The town was once a part of Exeter known as Brentwood (or Brintwood) Parish. It was named after Brentwood, Essex, originally called “Burnt Wood”, where, in 1177, King Henry II granted permission for 40 acres (160,000 m2) of the king’s forest to be cut, burned and cultivated. Beginning in 1738, residents living in the southwestern portion of Exeter, now Brentwood and Fremont, petitioned to be set off, but were denied. They cited difficulty of getting to the Exeter church/meetinghouse, where weekly attendance was obligatory, and the requirement to pay Exeter taxes. Eighteen people wrote in dissent, saying that even the proposed new town would require travel more than two miles to a new meetinghouse.:4
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