Historical clue formulations

• Nev. neighbor — 2020-11-29
• Tombstone locale: Abbr. — 2019-12-21
• PHX airport locale: Abbr. — 2017-03-15
• Only non-Southern state won by the G.O.P. in '64 — 2014-07-27
• Calif. neighbor — 2013-03-06
• Home state of the 1964 and 2008 Rep. presidential candidates — 2011-12-29
• Phoenix's home: Abbr. — 2011-02-28
• Mex. neighbor — 2011-01-14
• 48th state: Abbr. — 2010-09-26
• Home of Snowflake, which, ironically, gets very little snow: Abbr. — 2008-12-04
• Phoenix's home: Abbr. — 2007-02-26
• London Bridge's home now: Abbr. — 2005-12-04
• Home of the Diamondbacks: Abbr. — 2005-08-17
• Phoenix's state: Abbr. — 2002-07-29
• McCain's state: Abbr. — 2002-05-21
• Mex. neighbor — 2001-09-23
• Sen. McCain's state: Abbr. — 2000-12-12
• Home of Organ Pipe Cactus Natl. Mon. — 2000-04-13
• Nev. neighbor — 1999-07-28
• Neighbor of Mex. — 1999-06-14
• N.M. neighbor — 1997-07-28
• N.M. neighbor — 1996-06-10
• Calif. neighbor — 1996-04-12
• Mesa's location: Abbr. — 1996-01-09
• U.S. terr until 1912 — 1995-02-21
• ZIP codes starting 85- and 86-: Abbr. — 1993-12-25