Adamstown (Pennsylvania Dutch: Adamschteddel) is a borough in Lancaster County which has grown into Berks County in the U.S. state of Pennsylvania. The population was 1,789 at the 2010 census. Of this, 1,772 were in Lancaster County, and only 17 were in Berks County. It was initially founded on 4 July 1761 by William Addams on the site of a former village of native Americans, and Addams named the community "Addamsburry". The community was incorporated as a borough on 2 April 1850.