Simplify the following text for a Grade 9 native English-speaking person.
Original: Howard Zinn ( August 24 , 1922 â `` January 27 , 2010 ) was an American historian , author , political activist , playwright , intellectual and Professor of Political Science at Boston University from 1964 to 1988 .
Simplified: Howard Zinn ( August 24 , 1922 â `` January 27 , 2010 ) was an American historian and professor .