Question: How many decades did the career of the American actor, who starred in "The Happy Ending," span?
Sentence (from "John Forsythe"): John Forsythe (born either John Lincoln Freund or Jacob Lincoln Freund; January 29, 1918 – April 1, 2010) was an American stage, film/television actor, producer, narrator, drama teacher and philanthropist whose career spanned six decades.
Relevant evidence: Yes