Historical clue formulations

• Agent — 2026-07-30
• He's a head of the pack — 2025-06-01
• Pack man — 2021-11-20
• Leading man? — 2019-07-13
• Leader of the pack — 2017-04-14
• First mate? — 2010-12-18
• Leader of the pack — 2009-11-06
• 38-Across, in a sense — 2007-06-05