Selma Mansion is one of the oldest structures in Norristown, Pennsylvania. Located on the western edge of the town, Selma was built by General Andrew Porter in 1794 around an existing structure purchased from Alexander McCammon in 1786. Porter was a soldier during the American Revolutionary War and helped found the Continental Marines, forerunner of the U.S. Marine Corps. He was later appointed Surveyor General, helped lay out the borders of the commonwealth and attained the rank of general.