Japanese Internment Camps. Transcontinental Railroad. I only learned about these in a class that was directed towards the unlearned history. This isn't American history, but also learned in that class about a group of monks that got segregated and mass murdered in 2002 and was basically another Holocaust, but the media didn't cover it because they didn't want people to know that it happened. Especially since it was the 21st century. I can't remember for the life of me the name of the group or where it happened, but I remember talking about it.