I figured I’d ask here since you comrades know history and are on talking terms with reality, unlike a lot of stuff that is available to read online. I am really looking for a short answer, although I know there were many factors playing out over a long long time. Just the bullet points, if you please.

Edit: Thank you for these awesome answers, a lot of exactly what I was looking for and a lot of new directions to explore. Y’all really are the dope-ass bear B-)