James Gilmore Backus (February 25, 1913 – July 3, 1989) was an American radio, television, film, and voice actor.
 Among his most famous roles were the voice of nearsighted cartoon character Mr. Magoo, the rich Hubert Updike III on the radio version of "The Alan Young Show", Joan Davis' character's husband (a domestic court judge) on TV's "I Married Joan", James Dean's character's father in "Rebel Without a Cause", and Thurston Howell III, on the 1960s sitcom "Gilligan's Island".
 He also starred in his own show of one season, "The Jim Backus Show", also known as "Hot Off the Wire".
Morey Amsterdam (born Moritz Amsterdam, December 14, 1908 – October 27, 1996) was an American television actor and comedian, best known for the role of Buddy Sorrell on CBS's "The Dick Van Dyke Show" from 1961 to 1966.
The Famous Adventures of Mr. Magoo is an American adult animated sitcom, produced by United Productions of America, which aired for one season (1964 –1965) on the NBC network (usually on Sundays from 6:30-7:00PM Eastern).
 The television series was based on the original cartoon of the same name, with Jim Backus reprising the voice over of the role he did on TV: while doing this show, he continued with the prime time show "Gilligan's Island".
Tag the Gag is a very short-lived television series which aired in 1951 on NBC.
 According to IMDb, it lasted two episodes.
 It was a panel game show, a popular genre at the time.
 However, "Tag the Gag" proved unsuccessful with viewers and critics.
 It was hosted by Hal Block, best known as a regular panelist on the popular and well-received series "What's My Line?
".
 Also featured were Morey Amsterdam, Harvey Stone, Herkle Stiles, and Jean Carroll.
 The archival status of the series is not known, and it is possible (though not confirmed) that it was wiped.
Wilson D. "Pete" Burness (June 16, 1904 – July 21, 1969) was an American animator and animation director.
 He won two Academy Awards during his career and was perhaps best known for his work on the Mr. Magoo series.
 He also contributed to the "Tom and Jerry" series, "Looney Tunes", "Merrie Melodies", and "Rocky and His Friends".
Jane Kean (April 10, 1923 – November 26, 2013) was an American actress and singer, whose career in show business spanned seven decades and included appearing in nightclubs, on recordings, and in radio, television, Broadway and films.
 Among her most famous roles were as Trixie Norton on "The Honeymooners" with Jackie Gleason, and as the voice of Belle in the perennial favorite "Mister Magoo's Christmas Carol".
Mister Magoo's Christmas Carol is a musical adaptation of Charles Dickens's famous short story "A Christmas Carol" starring the cartoon character Mr. Magoo.
 Aside from the 1950 marionette special "The Spirit of Christmas", it was the first animated holiday program ever produced specifically for television, originally airing in December 1962, and the only one until the stop-motion special "Rudolph the Red-Nosed Reindeer" was first shown in December 1964.
 The special also inspired the 1964 TV series "The Famous Adventures of Mr. Magoo".
 It featured the voice of Jim Backus as Magoo, with voice-over appearances by Paul Frees, Morey Amsterdam, Joan Gardner, and Jack Cassidy.
James Bernard Hausner (May 5, 1909 – April 1, 1993) (Another source gives May 20, 1909, as his birth date.)
 professionally Jerry Hauser was an American radio and television actor, best known as Ricky Ricardo's agent in "I Love Lucy" and as the voice of Waldo in "Mr. Magoo" and several characters such as Hemlock Holmes, The Mole, Broodles and Itchy in "The Dick Tracy Show" (he had also worked as a dialogue director for both of these cartoons).
Alan Young (born Angus Young; November 19, 1919 – May 19, 2016) was a British-born Canadian-American actor, voice actor, comedian and radio and television host/personality who "TV Guide" called "The Charlie Chaplin of Television".
 He was best known for his role as naive Wilbur Post in the television comedy series "Mister Ed" (1961–1966).
 Young was also the voice of Disney's Scrooge McDuck for over thirty years, first in the Academy Award-nominated short film "Mickey's Christmas Carol" (1983) and in various other films, TV series and video games until his death.
 During the 1940s and 1950s, he starred in his own variety/comedy sketch shows "The Alan Young Show" on radio and television, the latter gaining him two Emmy Awards in 1951.
 He also appeared in a number of feature films, starting from 1946, including the 1960 film "The Time Machine" and from the 1980s gaining a new generation of viewers appearing in numerous Walt Disney Productions films as both an actor and voice actor.
United Productions of America, better known as UPA, was an American animation studio active from the 1940s through the 1970s.
 Beginning with industrial and World War II training films, UPA eventually produced theatrical shorts for Columbia Pictures, notably the Mr. Magoo series.
 In 1956, UPA produced a television series for CBS, "The Boing-Boing Show," hosted by Gerald McBoing Boing.
 In the 1960s, UPA produced syndicated Mr. Magoo and "Dick Tracy" television series and other series and specials, including the popular "Mister Magoo's Christmas Carol".
 UPA also produced two animated features, "1001 Arabian Nights" and "Gay Purr-ee", and distributed Japanese films from Toho Studios in the 1970s and 1980s. "
Gerald McBoing Boing" (2005–2007) is a more recent television series based on UPA's memorable character and licensed and co-produced by Cookie Jar Entertainment and Classic Media, for Cartoon Network.

Question: Morey Amsterdam who was the voice of Mr. Magoo in Mister Magoo's Christmas Carol was best known for what role?
Answer: Buddy Sorrell