Historical clue formulations

• Purchase of proof? — 2019-05-05
• It comes in fifths — 2010-04-08
• What virgin drinks lack — 2007-09-19
• Still stuff — 2003-03-21
• Second part — 2003-01-12
• See 71-Across — 2001-06-12
• Matter of proof? — 2000-06-22
• Spirits — 1998-05-07
• Driving hazard — 1997-05-25
• Prohibitionists would like to prohibit it — 1996-12-24