20. Thesis Topic:  The Bear Flag Revolt, The Mexican War, and the Gold Rush,  Thesis Statement:  The State of California’s lack of a north south dividing line is not the result of geography but great historical events.  The central valley and northern California were fated to join the United States as a result of the Bear Flag Revolt and the Gold Rush, while southern California’s break from Mexico probably required the Mexican-American war to occur.  Therefore the size and shape of the modern State of California was greatly determined by the Mexican-American War.