Since the 1960's, the sport of American football has maintained its stranglehold as the most popular sport in the United States. Both in viewership and participation, football has a massive lead on all other sports, but as of late many factors have led some to believe that trouble could be on the horizon. With various issues including head injuries, player protests, and television viewership decline plaguing football and its professional league, the NFL, the door could be open for another collision sport from across the pond to surge in popularity: rugby. Played in 119 countries by millions of people, rugby is currently one of the most popular sports in the world, but because of American football's dominance in the U.S. it has yet to really find its footing here; however, despite its popularity paling in comparison to football, rugby is actually the single fastest-growing sport in the U.S. Both sports share some strong similarities, and with football facing a myriad of issues, there is real reason to believe that rugby could be on the rise while football could continue to falter. By reading through articles and statistics on the subject, this thesis was divided into four main analysis topics to compare and contrast the two sports: injury problems and how they affect viewership and participation, international following for each respective sport, culture around the games themselves and how it could appeal to American viewers, and potential for growth domestically. By examining these factors within both sports, I was able to come to the conclusion that rugby's potential to take hold in the U.S. is growing, and in the coming years as American football's safety and importance continue to be called into question, rugby could one day even supplant football as the most popular collision sport in the country.