Plumber in Chelmsford, MA

The Pennacook inhabited the area for thousands of years prior to European colonization. Settler-colonizers from the adjacent communities of Woburn and Concord founded Chelmsford in 1652. An act of the Massachusetts General Court in the last week of May 1655 incorporated Chelmsford as a town; it was named after Chelmsford, England. The nearby communities of Groton and Billerica were incorporated at the same time. Chelmsford originally contained the neighboring town of Westford, as well as parts of Carlisle, Tyngsborough and a large part of Lowell (formerly known as East Chelmsford).

Successive Pennacook leaders Passaconaway and Wonalancet strove to maintain a friendship with the European settler-colonizers who founded Chelmsford within their territory. Despite this determinedly pro-peace stance, Chelmsford settlers became increasingly violent towards the tribe, often forcing the Pennacook to flee north temporarily or permanently. On one notable occasion, a handful of Pennacook who were too sick or elderly to flee with their kin remained behind and Chelmsford settlers burnt them alive in their dwelling. Eventually most Pennacook refugees permanently moved north to join relations in Odanak, but their descendants among the Abenaki First Nation and other tribes of the Wabanaki Confederacy continue to view Chelmsford as part of their ancestral and unceded homeland.

Several women of Chelmsford were suspected of being witches, such as Sarah (Hildreth) Byam and Martha Sparks. In 1691, Martha was held in the Boston Gaol for witchcraft, appeared in court, but was eventually set free after about a month. Some relate her freedom to the influence of the Chelmsford minister.