 Okay, so I kind of set you up, huh? You're probably not carrying a $500 bill. In fact, most Americans have never even seen a $500 bill. But here's the bigger question. Why do we even need a bill that big? You can hardly today even cash a hundred. But there really is a $500 bill. And the president's face on it? Our 25th president, William McKinley. And what is notable about President McKinley? Well, he was a Civil War veteran and the last veteran of that war to serve