Historical clue formulations

• Lowest-ranking G.I. — 2021-07-21
• Low-ranking G.I.: Abbr. — 2020-03-03
• Beetle Bailey's rank: Abbr. — 2019-04-21
• Lowest-ranking G.I. — 2015-03-02
• Cpl.'s inferior — 2010-11-21
• Lowest-ranking G.I. — 2009-11-09
• Grunt: Abbr. — 2006-12-06
• Enlistee: Abbr. — 2006-08-08
• See 37-Across — 2004-08-15
• Ryan was one: Abbr. — 2000-09-16
• Cpl.'s inferior — 2000-09-05
• Part of Pfc.: Abbr. — 2000-05-09