The New England Commonwealth was one of the thirteen commonwealths of the pre-war United States of America. Created in the early 21st century, it was comprised of the former states of Maine, New Hampshire, Vermont, Massachusetts, Rhode Island and Connecticut.
The Commonwealth is what is left of the pre-War American state of Massachusetts in New England. While traditionally called a commonwealth in itself, before the Great War, Massachusetts was also part of the New England Commonwealth of the United States in the alternate history of the Fallout universe. Most of it is a war-ravaged quagmire of violence and despair like much of the rest of the former United States, but it is also where the mysterious Institute is located.
- The Commonwealth (mentioned in Fallout 3 and Fallout: New Vegas)
- The Institute (mentioned in Fallout 3)