Millions of black people in the Jim Crow South were prevented from voting. That's the bad news. Fortunately, there's some good news. They were able to vote with their feet and millions of them did. In doing so, they benefited themselves both economically and politically, and also benefitted millions of white people in the North with whom they traded. What happened in the United States in the last century is dramatic evidence that voting with one's feet is much more powerful than voting at the ballot box. That experience has lessons for today's controversy over immigration to America.