Historical clue formulations

• Year "The Wonderful Wizard of Oz" came out — 2013-03-31
• Year "Tosca" premiered — 2013-02-16
• Year the Paris Métro opened — 2011-09-25
• Year McKinley was elected to a second term — 2010-04-20
• Century-ending year — 2004-12-10
• Year of the first Davis Cup matches — 2004-10-09
• 1900 — 1999-09-20
• Year the Paris Métro opened — 1998-04-18
• Turn-of-the-century year — 1998-02-06
• 1900, on a cornerstone — 1997-04-28