Howdy all -
I nominate Deganawidah, the Peacemaker, as a Historical Dude. Along with his compeer Ayenwatha, Deganawidah brought a message of "take 'er easy" to the Five Nations tribes who at the time were engaged in a perpetual tit-for-tat gutter-ballin' violence that harshed everyone's buzz. Deganawidah elucidated the Great Law of Peace, laying the foundation for the dudely Haudenosaunee, or Iroquis Confederation, which amazed later in-coming European refugees with its realization of, and respect for, dude-ish freedom for all.