According to the article, why did the Tulsa massacre “lay hidden for decades”?

Meeee i’m in need of answerering this

2read this passage from "the raven." what is puzzling the speaker in this stanza? 60% but the raven still beguiling my sad fancy into smiling, straight i wheeled a cushioned seat in front of bird, and bust and door then, upon the velvet sinking, i betook myself to linking fancy unto fancy, thinking what this ominous bird of yore- what this grim, ungainly, ghastly, gaunt and ominous bird of yore meant in croaking "nevermore." s and what the raven's message is why the raven came to visit where the raven came from how the raven got into his room

Read the sentence from last lecture by randy pausch. all right, so what we’re not talking about today, we are not talking about cancer, because i spent a lot of time talking about that and i’m really not interested. pausch tells his audience this because he wants them to know that