I'm surprised the US never found a love for rugby, it's a brilliant sport to play and spectate but it tends to be a fair bit less dangerous to its players than American football. There's various reasons but the lack of protective gear is a factor people talk about a lot ironically.

Interestingly go far back enough in time and they evolved from a common ancestor, but nowadays there's little to unite them other than fact they're both full-contact ball sports.