Historical clue formulations

• Lincoln in-laws — 2018-06-05
• Mrs. Lincoln's family — 2014-01-17
• Lincoln in-laws — 2012-04-01
• Lincoln in-laws — 2007-01-12
• Lincoln in-laws — 2002-07-20
• Lincoln's in-laws — 1996-07-22
• Lincoln in-laws — 1995-07-21
• Lincoln's in-laws — 1994-07-21