Should I believe this?

Childhood and pre-Hollywood career
The Marx family grew up on the Upper East Side (E 93rd Street) of New York City, in a small Jewish neighborhood sandwiched between Irish-German and Italian neighborhoods. Groucho's parents were Minnie Schoenberg Marx and Sam Marx (called "Frenchie" throughout his life).

Minnie's brother was Al Schoenberg, who shortened his name to Al Shean when he went into show business. He was half of Gallagher and Shean, a noted vaudeville act of the early 20th century. According to Groucho, when Shean visited he would throw the local waifs a few coins so that when he knocked at the door he would be surrounded by child-like adoring fans. Marx and his brothers respected his opinions and asked him on several occasions to write some material for them.

Minnie Marx did not have an entertainment industry career, but she had intense ambition for her sons to go on the stage like their uncle. While pushing her eldest son Leonard (Chico Marx) in piano lessons, she found that Julius had a pleasant soprano voice and the ability to remain on key. Even though Julius' early career goal was to become a doctor, the family's need for income forced Julius out of school at the age of twelve. By that time, Julius had become a voracious reader, particularly fond of Horatio Alger. Throughout the rest of his life, Marx would overcome his lack of formal education by becoming very well-read.

After a few comically unsuccessful stabs at entry-level office work and other jobs suitable for adolescents, Julius took to the stage as a boy singer in 1905. Though he reputedly claimed that in the world of vaudeville, he enjoyed only "modest success" but was "hopelessly average," it was merely a wisecrack. By 1909, Minnie Marx successfully managed to assemble her sons into a low-quality vaudeville singing group. They were billing themselves as 'The Four Nightingales', Julius, Milton (Gummo Marx), Adolph (Harpo Marx) (later changed to Arthur), and another boy singer, Lou Levy, traveled the U.S. vaudeville circuits to little fanfare. After exhausting their prospects in the East, the family moved to La Grange, Illinois to play the Midwest.

After a particularly dispiriting performance in Nacogdoches, Texas, Julius, Milton, and Arthur began cracking jokes onstage for their own amusement. Much to their surprise, the audience liked them better as comedians than singers. They modified the then-popular Gus Edwards comedy skit, "School Days", and renamed it "Fun In Hi Skule". The Marx Brothers would perform variations on this routine for the next seven years.

For a time in vaudeville all the brothers performed using ethnic accents. Leonard Marx, the oldest Marx brother, developed the "Italian" accent he used as "Chico" to convince some roving bullies that he was Italian, not Jewish. Julius Marx's character from "Fun In Hi Skule" was an ethnic German, so Julius played him with a German accent. However, after the sinking of the RMS Lusitania in 1915, public anti-German sentiment was widespread, and Marx's "German" character was booed, so he quickly dropped the accent and developed the fast-talking wise-guy character he would make famous.

The Marx Brothers became the biggest comedic stars of the Palace Theatre, which billed itself as the "Valhalla of Vaudeville". Brother Chico's deal-making skills resulted in three hit plays on Broadway. No comedy routine had ever infected the hallowed Broadway circuit. But reports are unanimous that the Broadway audiences were just as convulsed with laughter as the vaudeville ones had been. The Marx Brothers were now more than a vaudeville sensation; they were a Broadway sensation.

All of this predated their Hollywood career. By the time the Marxes made their first movie, they were major stars, with sharply honed skills, and when Groucho was relaunched to stardom on You Bet Your Life, he had already been performing successfully for half a century.