The U.S. Open is the final Grand Slam tournament of each tennis season, and 21-year-old Ethan Quinn can speak for every American when he says he loves being able to compete on home soil after a long year of traveling.But, of course, tennis is an individual sport, and each player in the tournament is battling to be the last one standing, including every American facing compatriots. Still, Quinn — entering his third U.S. Open with his highest career ranking at No. 84 — explained how tight-knit that group is despite the competitive environment.CLICK HERE FOR MORE SPORTS COVERAGE ON FOXNEWS.COMThe United