In most instances, people bring up the Jim Crowe era.
While civil rights laws did end Jim Crowe, that argument ignores that fact that it was Jim Crowe laws, not just some social movement. If your business treated black people equally you could get in trouble. Due to the laws at the time, we have no way of knowing what society would have done. I think that looking at more northern states shows that not all of society did or wanted to act that way.
I think the problem that we run into today is that we are getting a rebound effect. We keep talking about it, keep turning every little thing into a huge issue, and feeding the debate. If media reserved the race card for true and clear issues of racism, rather than pulling it out every chance they get, then maybe we will all calm down.