The show debuted at the Lyric Theatre in Allentown, Pennsylvania, before opening in nearby Philadelphia in May 1923. It opened at the Casino Theatre in New York City on May 19, 1924. Legend has it that the first-string critics for the New York papers were slated to see a different show premiering at the Winter Garden Theatre the same night, and only came to "I'll Say She Is" when the other show was postponed at the last moment. However, as both the Winter Garden and the Casino were part of the Shubert chain, it seems more likely that the openings were deliberately set for different dates to avoid competing with each other. In any case, the critics, notably Alexander Woollcott, who was only at the show because his other engagements were canceled, raved about the show, especially Harpo's performance, and the Marx Brothers became first-rank stars virtually overnight.