Where were you when Los Angeles attacked San Francisco? Did you serve on the U.S.S. Castro? Did you fight in the battle of Van Nuys? Painter Sandow Birk spent five years documenting his imaginary civil war between Northern and Southern California, creating epic battle paintings, spot-on propaganda posters and a mock-History Channel documentary. Neda Pourang visited Birk to find out why California's two major cities came to blows.