SP's streamlined Sunset carried a news agent coach that had a divider about midway in the car. The Guide noted this with the designation "partition". Colored passengers buying tickets in CA, AZ or NM where descreately assigned to this coach. Also, the dining cars on this train (and maybe others) had the two tables closest to the kitchen sectioned off by curtains. I once saw a "Jim Crow" combine of IC heritage somewhere but I can't remember where. I hope at least one was preserved as a reminder.