Quiz Nation! What Do You Know About MLK?

America's most prominent civil rights leader, Martin Luther King, Jr., would have been proud to see Barack Obama sworn in as president tomorrow if he had lived to see his 80th birthday. MLK's legacy of working for equality is celebrated each year. Watch this moving excerpt of his "I've Been to the Mountaintop" speech, given on the eve of his death, and take this quiz to find out what you know about the life Americans remember today.