| 2025-07-06 | Philosopher who wrote "The bureaucracy is a circle from which no one can escape" |
| 2020-10-26 | Karl who co-wrote a manifesto |
| 2020-08-02 | His tombstone reads "Workers of all lands unite" |
| 2019-01-20 | Influence on Castro and Mao |
| 2018-10-03 | "Das Kapital" author |
| 2018-07-24 | See 10-Down |
| 2018-01-06 | Who said "Revolutions are the locomotives of history" |
| 2017-09-06 | Who said religion "is the opium of the people" |
| 2016-10-30 | Who said "Revolutions are the locomotives of history" |
| 2016-05-30 | Funny Groucho or Harpo |
| 2015-12-25 | Who said history repeats itself "the first time as tragedy, the second time as farce" |
| 2015-02-16 | Harpo, Zeppo or Groucho |
| 2014-10-21 | Karl, Richard or Harpo |
| 2013-03-21 | Richard with the 1989 #1 hit "Right Here Waiting" |
| 2012-10-26 | "I have had a perfectly wonderful evening, but this wasn't it" speaker |
| 2012-07-17 | Groucho or Chico |
| 2011-04-11 | Karl with a manifesto |
| 2011-01-14 | "The Poverty of Philosophy" author |
| 2010-04-19 | Any brother in "Animal Crackers" |
| 2009-01-08 | Last name in comedy |
| 2007-07-25 | With 53-Across, noted comedy group, in brief |
| 2006-09-11 | Karl who philosophized about class struggle |
| 2006-08-10 | Philosopher who gave his name to an -ism |
| 2002-06-15 | Manifesto writer |
| 2001-10-28 | Out-of-favor icon |
| 1998-04-07 | "Manifesto" writer |
| 1997-03-12 | Zeppo, for one |
| 1996-10-20 | "Capital" fellow |
| 1996-09-16 | Groucho or Zeppo |
| 1996-01-01 | Communist Karl |
| 1995-08-24 | Pop singer Richard |
| 1995-04-30 | "Das Kapital" author |