Dutch Shultz isn't that unknown. I've seen his biography on TV, he's a key player in the film Hoodlum (played by Tim Roth) and i've read about him on Crimelibrary.com. I thought he was quite well known as the 'Beer Baron of the Bronx'.

Sorry mate but good idea for a post and good purpose for the post. I love the ironic question. If they're unknown, how would we know about them. Just messing mate.