It started as a parish of Exeter, and was granted full town privileges by the legislature in 1737. It was probably named for Newmarket in Suffolk, England. The Lamprey River, running through the town, was named for John Lamprey, whose name was Saxon for "a woodland enclosure where peace is to be found." For a while, the town was called Lampreyville. Newmarket was a center of the New England shipping trade with the West Indies.
Beginning with the first cotton textile mill in 1823, the Newmarket Manufacturing Company would dominate the mill town's waterfront and economy with seven textile mills harnessing water power at the falls.It built numerous support structures as well, including multi-family housing for workers. It also built dams upriver to create Pawtuckaway Pond in Nottingham and Mendums Pond in Barrington -- during drought, the company could release a regulated flow of water from the dams into the Lamprey to run the works. The company closed in 1929.[2] Its buildings are today listed on the National Register of Historic Places, and adapted for modern commercial and residential uses. In the 1970s, the mill served as the headquarters of the Timberland Company during the years when it transformed itself from a small work-boot manufacturer to a leading "urban" fashion brand. (The corporate headquarters are now located in nearby Stratham.)
Source: Wikipedia: http://en.wikipedia.org/wiki/Newmarket,_New_Hampshire.
Photo sources: New Market Historical Society