Nice, matsumoto. I like the idea of the Union and the CSA having a common foe.
Here are a couple I came up with:
Remember the Alamo
Date: March 7th, 1836
Location: San Antonio, Texas
Scenario: Antonio de Padua María Severino López de Santa Anna y Pérez de Lebrón, or Santa Anna, is basking in the glow of his victory over the Texans at the old Spanish mission, The Alamo. His victory is short lived when, the next morning, he finds his army besieged by a nightmarish force of gouls, ghosts, and zombies. The Texans have risen from the dead to avenge their defeat.
Participants: Undead Texans vs. The Mexican army
Key figures: Antonio de Padua María Severino López de Santa Anna y Pérez de Lebrón, William Travis’ skeleton, the ghost of Jim Bowie, Zombie Davy Crockett.
Date: Winter, 1777
Location: The American Colonies
Scenario: George III, in ordered to avoid the lose of the British Colonies in America, strikes a deal with the Unseelie Court. At the cost of his own sanity, he wins they support of the magical creatures of the British Isles. With Banshees, Sluagh, and even Old Shuck the hellhound swelling the ranks of his army in America, George III sees the tide of the war turn back in the monarchies favor. . . That is, until Ben Franklin strikes a deal with several Indian tribes. With their shaman on the side of the rabble, the war in the colonies enters a new magical phase.
Participants: The British Army with Unseelie allies vs. The Continental army with Indian shaman allies.