Opened on March 8, 1961. Closed December 12, 1964 after 1,572 performances — 3.8 years. Mary, Mary is a play by Jean Kerr. After two previews, the Broadway production opened on March 8, 1961, at the original Helen Hayes Theatre, where it ran for nearly three years and nine months before transferring to the Morosco, where it closed on December 12, 1964, after 1572 performances, making it the longest-running non-musical Broadway play of the 1960s. Wiki link