Short answers, pulled from the story.
The mother of the Marx Brothers was Minnie Marx, born Minnie Schoenberg in Dornum, East Frisia. She managed her sons under the pseudonym Minnie Palmer to avoid the stigma of a mother managing her own sons.
The Marx Brothers began their career in 1905 when a fourteen-year-old Julius Marx stepped onto a stage in New York City. They started as a singing act called The Three Nightingales in the immigrant quarters of the Yorkville district.
The Broadway show that launched the Marx Brothers to stardom was called I'll Say She Is. The production ran for 313 performances and was created with the intervention of Ned Wayburn and the Johnstone brothers.
Harpo was the Marx Brother known for playing a silent harp player with a curly wig. He developed this persona during the 1914 production Home Again alongside Groucho with his greasepaint mustache and stooped walk.
The Marx Brothers moved to Hollywood in 1929 and released their first film The Cocoanuts. This film was a direct adaptation of their Broadway hit and was notable for its use of sound technology.