Historical clue formulations

• George Ferris, for the Ferris wheel — 2018-06-19
• James Parkinson or Alois Alzheimer — 2017-02-02
• Earl of Sandwich, e.g. — 2013-05-31
• Louis Braille or Louis Chevrolet — 2012-10-02
• Rob Roy or Shirley Temple — 2011-06-10
• The Earl of Sandwich, for one — 2011-03-23
• Penn, to Pennsylvania — 2009-05-06
• Gabriel Fahrenheit or Anders Celsius — 2006-08-27