Acknowledging Columbus was a bastard goes goes all the way back to 1789, to the book "The History of the American Revolution", written by David Ramsay. It's a great history to read because it was written by one of the Revolutionaries themselves. It's not a re-interpretation by a modern college professor, but instead describes the Revolution from the revolutionary's own eyes.
The very first chapter describes how Columbus was evil in very modern terms:
"we see such an accumulation of good, as leads us to rank Columbus among the greatest benefactors of the human race: but when we view the injustice done the natives, the extirpation of many of their numerous nations, whose names are no more heard—the havoc made among the first settlers—the slavery of the Africans, to which America has furnished the temptation, and the many long and bloody wars which it has occasioned, we behold such a crowd of woes, as excites an apprehension, that the evil has outweighed the good"I point this out because of activists who fight against the consensus that "Columbus was good". That consensus doesn't exist -- everybody who has put anything thought into it agrees that "Columbus is bad". What we are really fighting against is inertia -- and that we don't want to give up a three-day weekend, for any reason.