In 1920, Liebman entered vaudeville as a sketch-comedy writer, and in 1924[2] or 1925[1] became social director at Camp Log Cabin[2] or the Log Tavern[1] in Pennsylvania. In 1932,[1] or 1933[2] he was named theater director at Tamiment, a Pocono Mountains resort, where he would remain for fifteen years.[1]
Concurrently, he made his Broadway theatre debut as a sketch writer, alongside others, including The Little King comic-strip cartoonist Otto Soglow, of the musical revue The Illustrators' Show. It ran five performances, January 22–25, 1936, at the 48th Street Theatre.[3] Undaunted by the short run, he went on to co-write, with Allen Boretz, the comedy play Off to Buffalo, featuring Hume Cronyn. This ran seven performances beginning February 21, 1939, at the Ethel Barrymore Theatre.[4]
Back at the Tamiment Playhouse, Liebman recalled, "I was doing all the writing myself" until 1938, when he began working with Sylvia Fine.[1] Fine introduced Liebman to her future husband, comedian Danny Kaye,[5] whose talent Liebman immediately realized.
He placed Kaye and comedian Imogene Coca in a Tamiment musical, The Straw Hat Revue,[1] which moved to Broadway's Ambassador Theatre on September 29, 1939, where it ran seventy-five performances through December 2. Liebman wrote the musical's book and is credited directorially under "staging". The cast included Coca, Kaye and Jerome Robbins.[6]
Yet another Tamiment discovery was Carol Channing, who said of Liebman: "He was the oracle.
If he approved, you were in show business."[7]
In 1948, he directed the sketches for the revue, Make Mine Manhattan, starring Sid Caesar in his Broadway theatre debut and later a star of Liebman's Your Show of Shows. Under his longtime guidance, Caesar emerged as one of TV's first superstars, a "comic genius." And as biographer David Margolick has written, "More than anyone else, Max Liebman made Sid Caesar Sid Caesar."[7]
Liebman also introduced to Broadway such Poconos performers as Betty Garrett and Jules Munshin, and the choreographer Lee Sherman,[1] with whom he worked on Make Mine Manhattan.