Simplify the following text for a Grade 6 native English-speaking person.
Original: Kurt Vonnegut , Jr. , ( ; November 11 , 1922 â `` April 11 , 2007 ) was one of the most influential American writers of the 20th century .
Simplified: Kurt Vonnegut , Jr. , ( ; November 11 , 1922 â `` April 11 , 2007 ) was an American writer . He influenced many other writers .