Fans of the undertaker, how long and from when to when, was he the american ?

I am a fan of his but not a fanatic, I was watching some match's on YouTube. when I saw a promo, with him wearing a support nomads shirt. I also saw him wearing what looked like, a support 81 shirt on him. I thought he was an lone wolf, or independent biker. Did he become affiliated with a club and when?