Unusual historical note I ran across:
Back in the early days of the Boy Scouts (1910), there was a Merit Badge titled "Master of Arms" which required the scout to train in Single Stick and Quarterstaff fighting, Fencing, Wrestling, Jiu-Jitsu, and Boxing.
http://www.bartitsu.org/index.php/2010/07/always-prepared-the-boy-scouts-and-self-defence/Kids were tougher then.
Scouts can now use Judo, Aikido, or Tai Ch'i to satisfy a requirement for the Sports Merit Badge, but Karate, Tae Kwon Do, and Boxing cannot be used, for the stated reason of avoiding liability for injuries (I think I've seen more long-term injuries in Judo/BJJ and Aikido than in the striking sports...)