In the 1800s, Plainfield was a thriving agricultural community, primarily producing sheep and leather for tanning.

With the widespread adoption of the steamship, and the resultant globalization in the 1870s, the expense of importing both mutton and leather from Australia and New Zealand was greatly reduced.

Consequently, the agricultural industries in Plainfield became less profitable, and the population declined substantially over the following decades.

Sixty-one men from Plainfield joined the Union Army late in the Civil War.

Plainfield sits 1620′ above sea level, and the peaks of West Mountain (at 2125′) are the highest elevation in Hampshire County.

Plainfield is bordered by the towns of Cummington, Ashfield, Hawley, Savoy, and Windsor.

The racial makeup of the town was 98.13% White, 0.34% Native American, 0.17% Asian, and 1.36% from two or more races.