Thats pretty much the case a certain person or group of people made the midwest families, new orleans,cleveland powerful and brought them to their height of power and kept everything intact and after they died the families lost alot of their power and started to be less and less active. These main powerhouses would be:
Kansas City- Civellas
Cleveland- John Scalise
St Louis- John Vitale
Milwaukee- Balistieris
Detroit-Tocco, Giacalones
Springfield- Joseph Zammuto
Rockford- Joseph Zammito
Dallas- Joe Civello
Tampa- Santo Trafficante