Grantham, N.H., was originally incorporated in 1761 and derived its name from a prominent man referred to as Thomas Robinson, Right Hon. Lord Grantham of Grantham, England. He was friends with Governor Wentworth, an activist for American independence and, later, one of Great Britain’s first postmaster-generals. The 1761 charter was granted to a group of 68 proprietors, but when the requirements for settlement were not met, the charter was forfeited. The second charter was granted in 1767 to another set of 70 proprietors (including one woman) for a town called New Grantham. The first settlers built homesteads in scattered areas on the west side of Grantham Mountain. Early settlements in Grantham included the Dunbar Hill area in the 1770s, the Leavitt Hill section around 1790-93 and Howe Hill around 1813. In 1790, the first year of the census, Grantham had 333 residents.
Established roadways in the early 1800s increased the town’s development, resulting in a church, store, cemetery, schoolhouse, two taverns and a blacksmith shop where the Meriden Road crossed the Croydon Turnpike. This area, well established by 1818, functioned as the town center. Also in 1818, the name was legally changed back to Grantham. Grantham has always had an entrepreneurial spirit. Early businesses included Francis Howe’s cooper shop (and later his son James’s commercial printing press) on Route 114, a clothespin factory run by Samuel Currier and a cider mill owned by Howard Green. Stores in Grantham date to the early 1800s when Francis Howard ran one at the Dunbar Hill settlement.
The lumber business played an important part in the economics of Grantham; by 1872 the town had six mills and claimed to saw more lumber annually than any other town in the county. These mills employed 26 people, had an annual payroll of $6,000 and sawed timber valued at $26,000. The economy of Grantham changed in the 1920s when wood grew scarce and several mills relocated or closed their doors. Grantham’s population declined from 550 to 275, and remained in that range for several decades.
In the mid-1970s, the Upper Valley-Lake Sunapee Council projected a population of 500 for Grantham in the year 2000. But the interstate and the need for more housing in the Upper Valley resulted in several Grantham residential developments such as Eastman, Olde Farms and Gray Ledges, boosting Grantham's population to 2,167 in 2000. The 2004 Census estimate for Grantham was 2,442 residents, which ranked the town 117th among New Hampshire's incorporated cities and towns.
“The first settlement in Grantham was upon the west side of the mountain, in 1767. Among the first settlers were Ezra Buswell, Elijah Gleason, Abel Stevens, Francis Smith, esq., Ithamer Bartlett, Job, Stephen and Caleb Colton, Jonathan Parkhurst, Jabez Bennett, Isaac Jenny, Ebenezer Burr, Rob’t and Charles Scott, Samuel, John and Rob’t Duncan, William Moulton, Ebenezer Stebbins, Abner Johnson, Parker Carr, Joab V. Young, Willard Marcy James Smith and William Huntington." – History of Grantham, by L. D. Dunbar