American football is the all-but-official sport of the United States. But for all the media coverage it draws, the origin story of football gets missed. How did this game become compelling enough to hold the United States in its thrall? The answer lies in the career of Walter Camp, whom contemporaries called the “father of American football.”

Camp worked on the game his entire adult life, a devotion that began in the second decade after the Civil War. On November 13, …