Historical clue formulations

• N.Y.C. subway letters — 2026-09-21
• Inits. at Grand Central Terminal — 2025-11-30
• Letters on an N.Y.C. fare card — 2025-05-08
• Underground org. of New York — 2023-11-01
• Letters seen all around New York City — 2023-06-23
• Big Apple subway inits. — 2023-06-18
• N.Y.C. commuter rail overseer — 2023-05-14
• N.Y.C. commuting inits. — 2022-02-20
• Org. at Grand Central Terminal — 2021-12-03
• Big Apple subway inits. — 2021-08-04
• Underground org. in N.Y.C. — 2020-11-27
• Letters on an N.Y.C. fare card — 2019-09-04
• N.Y.C. subway overseer — 2019-04-02
• N.Y.C. subway letters — 2019-03-28
• Overseer of trains, for short — 2019-02-02
• Underground org. in N.Y.C. — 2018-11-14
• N.Y.C. subway org. — 2018-11-11
• Subway operator, for short — 2018-10-26
• Travel org. with an eTix app — 2018-01-18
• Staten Island Railway inits. — 2017-11-24
• N.Y.C. subway letters — 2017-11-12
• Letters on N.Y.C. trains — 2017-09-17
• N.Y.C. subway overseer — 2017-06-06
• N.Y.C. org. that operates 24/7 — 2016-10-16
• New York rail and bus inits. — 2016-10-05
• Inits. at Grand Central Terminal — 2016-06-12
• 1959 Kingston Trio hit — 2016-03-11
• N.Y.C. subway overseer — 2016-01-26
• Kingston Trio hit that inspired the CharlieCard for Boston commuters — 2015-06-15
• Grand Central org. — 2015-04-23
• N.Y.C. rail org. — 2015-02-19
• Subway inits. — 2014-07-12
• N.Y.C.-based grp. with its own police department — 2014-02-07
• Overseer of N.Y.C. subways — 2014-01-14
• What Charlie rides, in a 1959 hit — 2013-12-18
• Where Charlie may ride forever, in song — 2013-08-25
• It has a Bridges and Tunnels div. — 2013-06-15
• N.Y.C. commuters' inits. — 2012-10-03
• Overseer of N.Y.C. bridges — 2011-11-30
• Rail org. — 2011-05-22
• Kingston Trio hit of 1959 — 2011-04-12
• Big Apple mass transit inits. — 2011-03-07
• N.Y.C. subway inits. — 2011-01-13
• 1959 hit with the lyric "Did he ever return? No, he never returned" — 2010-10-14
• N.Y.C. bus insignia — 2010-01-31
• N.Y.C. commuter option — 2007-11-22
• A train grp. — 2006-07-01
• Training org.? — 2005-09-15
• N.Y.C. subway overseer — 2004-12-01
• 1959 hit song set on "a tragic and fateful day" — 2004-11-27