Westfield is a city in Hampden County, in the Pioneer Valley of western Massachusetts, United States. It is part of the Springfield, Massachusetts Metropolitan Statistical Area. The population was 41,094 at the 2010 census. The ZIP Code is 01085 for homes and businesses, 01086 for Westfield State University and U.S. Post Office boxes.
The area was originally inhabited by the Pocomtuc tribe, and was called Woronoco (meaning "the winding land"). Trading houses were built in 1639-40 by settlers from the Connecticut Colony. Massachusetts asserted jurisdiction, and prevailed after a boundary survey. In 1647, Massachusetts made Woronoco part of Springfield, Massachusetts. Land was incrementally purchased from the Indians and granted by the Springfield town meeting to English settlers, beginning in 1658. The area of Woronoco or "Streamfield" began to be permanently settled in the 1660s. In 1669 (OS), "Westfield" was incorporated as an independent town; in 1920, it would be re-incorporated as a city.
From its founding until 1725, Westfield was the westernmost settlement in Massachusetts Colony. Town meetings were held in a church meeting house until 1839 when Town Hall was erected on Broad Street. This building also served as City Hall from 1920 to 1958. Due to its alluvial lands, the inhabitants of this area were entirely devoted to agricultural pursuits for about 150 years.