One of the original border towns, this territory was first granted in 1752 as Monadnock No. 6. In 1774, it was renamed Packersfield after Thomas Packer, high sheriff of Portsmouth, who was one of the Masonian Proprietors. In 1777, some residents petitioned to rename the town Sullivan. The petition failed, but in 1786, a portion of the town was combined with part of Gilsum and Keene to form the town of Sullivan. Packersfield kept that name until 1814, when it was renamed in honor of Lord Horatio Nelson, who died on board the British ship Victory in the war against Napoleon.

Population change for Nelson totaled 488 over 56 years, from 222 in 1960 to 710 in 2016. The largest decennial percent change was a 45 percent increase between 1970 and 1980, accounting for just over one-fourth of the total numeric change. The 2016 Census estimate for Nelson was 710 residents, which ranked 206th among New Hampshire's incorporated cities and towns. This town has 32.4 persons per square mile of land area. (info from NHES website)