[added Oct. 8, 2023. So I guess that the most probable locations for the Addams family in the Addams Family (1965) by Jack Sharkey, 1965, should be in the area around Parris Island, South Carolina, or the area around Jacksonville and Saint Augustine, Florida, or the area around Pensacola, Florida and Mobile, Alabama, or the area around Natchez, Mississippi. And the last three areas seem more probable because the USA acquired them directly from Spain.]
[added 10-09-2023. That same chapter says that Uncle Fester served in the Continental Army during the Revolutionary War. That might indicate Fester came from one of the 13 colonies, but he might have been a more or less foreign volunteer like Lafayette, von Steuben, Pulaski, etc.]