Malebolgia

 was the 51st state admitted to the United States of America. It was located on the mainland of the United States, thus indicating it was somehow formed from the division of pre-existing states. The Brigadier was sent there, after having helped establish the devolved parliament of Scotland, in order to give the fledgling state what experience he had learned. The eighth Doctor and Charley Pollard mistakenly landed there at the same time as the Brigadier, despite trying to land in San Francisco so as to see Dr. Grace Holloway. What the Doctor, Charley and the Brigadier found in was a right wing fundamentalist politician who was, with essentially the devil's help, attempting to seize the governorship and then the presidency. The trio helped expose would-be governor Brigham Elisha Dashwood III's demonic connections, thereby ending his political career and setting the new state on a different path. (BFA: Minuet in Hell)
 * ''The exact geographic location of this fictional state is never made clear. However, it does appear to be on the mainland, probably somewhere in the southeast.