A hundred and fifty years ago today a battle broke out at Fort Sumter near Charleston, South Carolina. That fight would later be seen as the start of the Civil War. The date the war started is clear, but the reason the war started is more complicated. A recent Pew Research Center study found that Americans are split on whether the war was mainly about states' rights or slavery. A lesser known reason for the war involved western states like California. Here to talk about that is the director of the Huntington - USC Institute on California and the West, William Deverell.