This place is very cool telling all about the history of the mob from Italian immigration and the Italian roots to the mob being involved with the unions. But be fore told here that this is a rather large museum. To go through it, it took us a good almost 3 hours and we did not even stop and read everything or watch all the short films provided or play with all the little exhibits. Has information on every mob/ organized crime person out there. So give yourself plenty of time.
The building that it is in is also very cool. If you are staying downtown it is a short walk which was nice. No need for taxis.