With the railroad came increasing development in those areas.
In addition to the Fitchburg Railroad, two others crossed the town: the Nashua and Acton, and the Framingham and Lowell.
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.
23.0% of all households were occupied by individuals 65 years of age or older living alone. For every 100 females age eighteen and over, there were 94.2 males.
Acton has nine drumlins — hills which are composed of glacial till.
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 population density was 1,080.5 per square mile (417.0/km²).
There were 8,530 total housing units, 96% of which were occupied, at an average density of 384.6 per square mile (148.5/km²).