The Tulsa Race Riot
of 1921, which most Americans today probably know nothing about, would make a great docudrama. Actually calling it a "riot" is an understatement -- it was more like a small war.
I've always wanted to see an epic-scale, fact-based disaster flick about the Halifax Explosion
of 1917, which destroyed half the city and left at least 2000 dead and thousands more injured.