Historical clue formulations

• Mack of early slapstick — 2016-11-06
• Director Mack of early slapstick — 2014-01-05
• Pioneer of slapstick cinema — 2012-11-17
• Rival of Roach in early film comedy — 2009-04-04
• Producer of the Keystone Cops films — 2007-11-18
• Mack ___, who created the Keystone Kops — 2003-11-23
• "Keystone Kops" producer — 2000-07-23
• Keystone Kops producer Mack — 1999-03-19
• "Keystone Kops" producer — 1997-04-06
• Keystone Kops creator — 1994-12-02