Acton is a suburban town in Middlesex County, Massachusetts, United States about twenty-one miles west-northwest of Boston along Route 2 west of Concord and about ten miles (18 km) southwest of Lowell. The population was 21,929 at the 2010 census.
Acton was first settled by Native Americans who used the Assabet, Sudbury and Concord rivers for transportation and the fields for farming seasonal crops. There is evidence of Native American settlements in Acton which go back 7000 years. When the colonists arrived in this area, the Native American population dropped dramatically due to European diseases for which they had no immunity.Concord was the first in-land colonial town established in the MA Bay Colony. The original boundaries of Concord included all of Acton and residents used the Acton land as grazing fields for their animals. In 1639, the first homestead was built within the modern day boundaries of the town..Acton was established as an independent town on July 3, 1735. Acton has held annual town meetingssince 1735, the records of which are held at Acton's Memorial Library.During the 19th century, Acton participated in the growing Industrial Revolution. By the mid-19th century, Acton was an industrial center for the production ofbarrels (cooperage). There were also a powder mill, three gristmills and four sawmills in town. The American Powder Mills complex extended downstream along the Assabet River and manufactured gunpowder from 1835 to 1940.On October 1, 1844 the railroad came to Acton.