GREENFIELD, a town of Massachusetts, U.S.A., on the Connecticut river; county seat of Franklin county. It is the eastern terminus of the Mohawk trail, and is served by the Boston and Maine railroad. It has an area of 20 sq. m., and a population in 1925 of 15,246, 15,50o in 193o Federal census. It is a busy trading centre, and has diversified manufacturing industries, producing more screw-cutting tools than any other place. The factory output in 1927 was valued at $7,669,188. A winter sports carnival is held here annually. Greenfield was settled in 1686 and incorporated as a district of Deerfield in 1753 and as a separate town in 1775. It was a centre of disaffection during the Shay's Rebellion.