From wiki:
He was known for playing Lou Grant during the 1970s and early 1980s, on both The Mary Tyler Moore Show and its spin-off series Lou Grant, making him one of the few television actors to portray the same character in both a comedy and a drama. He was the most honored male performer in the history of the Primetime Emmy Awards, having won seven – five for portraying Lou Grant (three as Supporting Actor in a Comedy Television Series and two as Lead Actor in a Dramatic Television Series). His other Emmys were for performances in two television miniseries: Rich Man, Poor Man (1976), where he won for Outstanding Lead Actor for a Single Performance in a TV series, and Roots (1977), for which he won for Outstanding Single Performance by a Supporting Actor in a TV series.