The famous phrase "Well, who you gonna believe, me or your own eyes?" is often referred to as a Groucho quote, but it was actually delivered by Chicolini (Chico Marx) in Duck Soup (1933) while impersonating Rufus T. Firefly (Groucho).
The FBI had a file on him after he made some jokes about communism.
The Marx Brothers classic 1937 comedy, A Day at the Races , was filmed at the Santa Anita Race Track (285 W. Huntington Drive) in Arcadia, CA.
The success of The Marx Brothers at MGM was due to the genius of Irving Thalberg. Upon his untimely death, the quality of their films declined mainly because studio chief Louis B. Mayer did not care for them or their act.
There are at least two versions of how Julius Henry Marx got his more famous nickname. One is that it came from his general disposition. The other, that, during the Marx Brothers' early days in vaudeville, he was the keeper of the act's "grouch bag" or money purse. Groucho, himself, said, on one occasion, "my own name, I never did understand."
There's a famous club in London called the Groucho, frequented by actors and celebrities. It got its name from the famous Groucho quote that he would not join any club that would accept him as a member.
Was a big fan of Gilbert & Sullivan (William S. Gilbert and Arthur Sullivan) operettas and used to stage Gilbert & Sullivan sing-along evenings at his home. During the 1950s he appeared as Ko-Ko on NBC-TV in an acclaimed abridged version of "The Mikado.".
Was a close friend of "The Exorcist" author William Peter Blatty.
Was good friends with rock star Alice Cooper, often inviting him over at 11:00 pm to watch TV. A drawing of Groucho can also be seen on the cover of "Alice Cooper's Greatest Hits" album. In 1978, when the original giant white letters of the famous "HOLLYWOOD" sign were auctioned off in order to raise money for new replacement letters, Alice bought an "O" in memory of Groucho.
Was in attendance at The Beatles 1964 Hollywood Bowl concert, and there is existing footage of him applauding.
Was intended to make a joke on the set of William Friedkin's The Exorcist (1973) by appearing in Father Merrin's clothes when Ellen Burstyn opened the door. However, the idea was dropped due to scheduling conflicts.
Was named, as The Marx Brothers, the #20 Greatest Actor on The 50 Greatest Screen Legends List by The American Film Institute.
Was never much of a womanizer in real life (as were his older brother, Chico Marx & Harpo Marx), having joked later in life about his disastrous attempts at courting as a young man.
Was the quiet, introverted middle brother of 5, and suffered the middle sibling condition. He never got as much attention as his older brothers (Chico Marx & Harpo Marx), who were wild and charming, or his two younger brothers (Zeppo Marx & Gummo Marx), who were cuter. The plus side of this outsider status was that he developed a cutting wit to get attention.
Was told by studio executive Walter Wanger to lose the greasepaint moustache as it was an "obvious fake". (Source: Joseph Adamson III in his book Groucho, Harpo, Chico and sometimes Zeppo (1973)
When he died in 1977, he left an estate valued at $2 million.
When talking about Margaret Dumont, the actress who frequently played the dowager who acted as a punching bag for Groucho's verbal insults, he claimed the secret to their chemistry is that she never understood what he was saying.