Looks like a posthumous pardon would be fitting in Johnson's case. I saw the documentary of the big fight in 1910 on PBS the other night. Couldn't turn the channel, which is sayin' something. The footage from the fight and all elements of the documentary were stunning.
There is a nice flashplayer sequence on the PBS site, which is mainly slides so it doesn't require too big a set of pipes. Who knew Jack London was such a bigot, but bigots were in no short supply then...and even today, bogotry remains.