Historical clue formulations

• Layers of stone — 2020-02-27
• They put up walls — 2014-03-02
• Stonewallers? — 2011-10-30
• Members of Grand Lodges — 2009-12-10
• "National Treasure" group — 2008-02-10
• Bricklayers — 2006-05-08
• Some fraternity members — 2005-09-10
• Fraternal group — 2004-11-30
• "Free" people — 1999-11-14
• Secret fraternity — 1997-11-28