My dad told me a story just last night about growing up in Texas. He remembers there being segregated buses, water fountains, and so on. He says that one time, his family took a black friend to the local swimming pool (there were four children, the friend was the same age as one of them) and they were asked to leave. Apparently they never went back. This would've been the sixties, maybe early seventies. Dad was young enough that at the time, he didn't really understand what was going on or why they didn't go back. so probably sixties. The KKK marched on the main street of my home town in Delaware not too many years ago. Early 90s, I think.
It's hard to believe that such things were once the norm. At least when the KKK marches now, they are considered to be a radical fringe organization, for the most part. I can't imagine a world where they are considered normal.