Historical clue formulations

• Collection of offers? — 2020-09-12
• Group with many hits — 2015-09-26
• What a 5-Across is a boss in — 2015-06-24
• Hit makers? — 2009-10-09
• Organized crime — 2007-07-11
• Cosa Nostra — 2005-06-02
• Don's business — 2001-06-03