As the 20th century continues, America faces perhaps its most daunting challenges yet. The 1930s brings the greatest economic crisis in its history; Pearl Harbor is a lightning bolt to the American soul; the U.S. elects its youngest commander-in-chief, 46-year-old John F. Kennedy; and on a bridge over the Alabama river, Martin Luther King's fight for equal rights will face its fiercest test. Then, on a September morning in 2001, America faces a new crisis.