Throughout the 20th century, football grew to be America's new pastime - and as the sport's popularity grew, so did the NFL's fortunes. From early league leadership to the Pete Rozelle era, the NFL successfully warded off rival league challengers and became the preeminent economic juggernaut of the American sports landscape. But as the NFL's financial dominance has grown, so has its risk exposure to certain elements of its 20th century business model. In this case, students will work to understand the NFL's monopolistic business model and how it has fueled the NFL's financial windfalls over the past several decades. Students will also gain an understanding of the history of rival football leagues in America in order to analyze the question facing the modern NFL management team: is its business model vulnerable to disruption by a handful of well-funded rival leagues set to start play in 2019?