Book excerpt: The Super Bowl redefined American sports. Over the past half century, the NFL's championship game has grown from humble beginnings to the biggest sporting event of the calendar year--an event that creates legendary stories, from Len Dawson's conversation with the president to Jim O'Brien's game-winning kick and Randy White's post-game duet with Willie Nelson. Covering 50 Super Bowls, from 1966 through 2016, this book gives an insider's view of each game, with recollections from the people who participated, many told for the first time.