Historical clue formulations

• Center of activity — 2026-06-16
• Major airport, e.g. — 2025-07-14
• Kennedy for American, e.g. — 2024-11-17
• Place with many airline connections — 2023-07-10
• Pivotal part of a revolution — 2023-03-17
• Center of activity — 2022-11-14
• Center — 2022-10-09
• Where many connections are made — 2020-09-19
• Nucleus — 2019-07-20
• Likely spot for a layover — 2019-05-11
• Relatively easy city to fly into and out of — 2018-07-27
• Wheel's center — 2016-09-12
• Airline's base of operations — 2016-08-08
• Nerve center — 2016-06-16
• Airport with many connecting flights — 2015-12-29
• Nucleus — 2015-09-20
• LAX or ORD, to United — 2015-04-22
• Center — 2015-02-10
• Trivial Pursuit board location — 2014-10-24
• Many a layover locale — 2012-11-09
• Turning point — 2012-10-25
• Center of a Trivial Pursuit board — 2012-05-09
• Big airport — 2011-10-19
• Wheel's center — 2011-02-14
• Indirect flight stop-off — 2009-05-10
• Atlanta, for Delta — 2009-01-19
• Important airport — 2007-11-07
• Center of activity — 2005-09-20
• Airline's home base — 2005-09-13
• Activity center — 2005-06-18
• Center of activity — 2004-08-16
• Where spokes meet — 2004-05-10
• Airline's home base — 2004-02-24
• Wheel's center — 2003-05-06
• Center — 2002-12-15
• Airline locale — 2002-10-13
• Busy airport — 2002-07-09
• Focal point — 2001-12-11
• Core — 2001-05-27
• Turning point — 2000-11-03
• Center — 1999-04-14
• Focus — 1998-11-25
• Meeting place — 1998-05-02
• Focal point — 1997-01-10
• Boston's nickname, with "the" — 1995-04-03
• Pivot — 1994-12-16
• Focus — 1994-12-03
• Center piece — 1994-07-30
• Spokes' intersection — 1994-02-21