Book excerpt: Through 100 evocative, often stunning photographs, as well as the stories that accompany them, Sports Illustrated visits the great arc of football, America's most popular spectator sport. From the dawn of the professional era, through the days of Vince Lombardi and Johnny Unitas, the westward expansion and the thrilling Super Bowls of today, football's rich and remarkable history is here. Unforgettable events such as the Greatest Game Ever Played, Joe Namath's guarantee before Super Bowl III and Nick Foles's Philly Special live in a continuum with stirring photos of the game's most beloved and largest personalities such as Jim Brown, Walter Payton, Bill Parcells, Tom Brady, Patrick Mahomes and many more. Sports Illustrated's unmatched storytelling is in high form in a book that renders exquisite anecdotes, and explores football's heritage and uniquely American character, all in unforgettable style.