James "Jimmy the Swede" Morand was an apparently Swedish-American fellow who was also a probable lookout during the Saint Valentine's Day Massacre operation along with Byron Bolton, with the shooting carried out by the rest of the American Boys. He's the only possible Swede I can think of off the top of my head.

According to Northsider expert Rose Keefe, there were about 200 members. They were a substantial mob. Like everyone has said, there isn't much in the way of evidence of a structured hierarchy. You've got a boss, his inner circle, and everyone else, and that's it. It was pretty horizontal.

You hear them called an "Irish Mob", but this isn't really accurate at all; they were a multiethnic gang, and of the identified members, it seems that there are more German-Americans than any other ethnicity, at least in the guys I can think of off the top of my head. They get the "Irish" designation from the prominence of O'Banion (who really was Irish, though he may have been Welsh if you trace his ancestry back far enough - not that that matters) and Moran (who wasn't really Irish at all).

That's off the top of my head, as I don't have my references with me at the moment. You need to read "The Man Who Got Away" and "Guns and Roses", both by Rose Keefe, and "The Saint Valentine's Day Massacre", by William Helmer and another fellow whose name escapes me.

I know quite a lot about the Northsiders really, at the risk of sounding arrogant... feel free to ask if you have any other questions. Did you go by the site of the Valentine's Day Massacre? I've been there; it's a parking lot and a retirement home now.

Coincidentally, I am going to be living on the North Side of Chicago starting later this year.