That's one way to kill the majority of a five hour flight but good luck staying awake through that movie. It should have been a five part PBS miniseries.
I was telling my daughter & son-in-law this weekend I thought Scorsese overdirected, and never let DeNiro and Leo portray the actual scummy evil they were, only hinting at it.
Fwiw historically, this went on during the same timeframe as the Greenwood massacre in Tulsa, not 80 miles away.