I happened to hear a story on Sound Beats the other day about a boxer of the early 20th century named Harry Willis. Harry Willis fought for some twenty years between 1911 and 1932 and at one time held the crown as the "Colored Heavyweight Champion".
A contemporaneous boxer, Jack Dempsey, refused to defend his heavyweight title againste Willis and other black boxers. Dempsey had his own color line. Dempsey was one of the most popular athletes of that time and one of the most popular boxers ever.
I mentioned this story not because it was remarkable but because at that time it was considered quite unremarkable. In the 1920s Dempsey's overt racism was not generally considered outrageous or an act of cowardice.
Dempsey is an Irish name. It's quite possible that Dempsey's parents and grandparents were victims bigotry against the Irish. "Help wanted. Irish need not apply" was a sign commonly seen in the windows of shops and stores in nineteenth-century America.
Racism and bigotry of all sorts were common in America. After all, we started this country with slavery as a major part of our labor force. The good news is that we are not as bigoted or as racist as our parents, grandparents and ancestors. However, it's quite possible that our descendants will judge our behavior critically.