Plainfield was incorporated in 1699. Le Comte de Rochambeau, Jean Baptiste Donatien de Vimeur, marched through and camped in the town during the American Revolutionary War on his way from landing at Narragansett Bay to join George Washington's forces on the Hudson River in 1781.
Plainfield proved to be an industrial heavyweight in the 19th and early 20th centuries due largely to the ability of the Moosup and Quinebaug Rivers to provide power to the different mills throughout town. Combined with the mills, Plainfield had incredible commerce for a small town because four railways from Hartford, New York, Boston, and Providence intersected within the town. There was also a highly acclaimed school on Academy Hill, which is how the present Academy Hill Road got its name.
