Philadelphia had a substantial Mafia faction under Angelo Bruno, "the gentle Don." Atlantic City, NJ, fell under the Philly mob. When casino gambling was legalized, the heat got turned up. Bruno was murdered. Then Phil "Chicken Man" Testa, his successor, was bombed. This set the stage for Nicodemo "Little Nicky" Scarfo, who came up out of AC and then ran the Philly mob. A nonstop string of murders brought him and his people to the attention of law enforcement--probably the biggest government takedown until the famous "Commission" case in NYC. I don't think Baltimore has a separate Mafia family--it may be dominated by one of the NYC families.