Is it racist to remind people that the American government first disarmed Native Americans and then decimated them?

A week or two ago, I put this poster on my site:

I think it’s an un-racist poster.  It reminds people that government will always be a minority’s worst enemies.

What I didn’t know was that, in Greeley, Colorado, someone put up a billboard echoing that sentiment:

The friend who sent me this video said exactly the right thing about those who are now crying foul:

I love the premise here: “Pay no attention to history, it may offend someone!”