Alstead was called Newton when it was granted to Samuel Chase and others. The town received its New Hampshire charter in 1763. Alstead was one of the towns that wavered in its allegiance after the Revolutionary War. It decided to join Vermont in April 1781, but returned to N.H. authority early the next year. The first paper mill in New Hampshire was established by Ephraim and Elisha Kingsbury in 1793 on Cold River.

While Alstead was basically an agricultural community, its streams and ponds once powered a variety of small mills. A turbine water mill at East Alstead is probably the last of its type anywhere in the region. Shedd-Porter Memorial Library, built in 1910 in neo-classic revival style, was a gift to Alstead and Langdon by native son John G. Shedd, an associate of Marshall Field’s department store in Chicago. Another native-son philanthropist, Charles M. Vilas, gave a large public recreation area, school building and the only carillon in Cheshire County. Marion Nicholl Rawson, chronicler of U.S. arts and crafts, made her home in Alstead.