The program -- American Football Without Borders ( AFWB ) -- is an effort by the NFL to spread the game 's popularity by helping those unfamiliar with American football understand it better .
American football is the most popular professional sport in the United States .
The program -- American Football Without Borders ( AFWB ) -- is an effort by the NFL to spread the game 's popularity by helping those unfamiliar with American football , the most popular professional sport in the United States , understand it better .