I played a civ4 scenario for the first time last night. I played the American Revolution as the British. The map was really neat to play on, as they duplicated the eastern US pretty well. Each side starts out with about half of the cities on the map. Various actions cause loyalists to join the British or Colonials to take up arms. Also, accurately enough, the British are reinforced by German Mercenaries. From time to time British reinforcements arrive in Canada.