Loosely based on the life of attorney Harold Krents, the plot revolves around a Manhattan blind man whose controlling mother disapproves of his relationship with a free-spirited hippie. The title was inspired by a passage in Charles Dickens' Bleak House: "I only ask to be free. The butterflies are free. Mankind will surely not deny to Harold Skimpole what it concedes to the butterflies."
After twelve previews, the Broadway production, directed by Milton Katselas, opened on October 21, 1969 at the Booth Theatre, where it ran for 1128 performances. The cast included Keir Dullea, Blythe Danner, and Eileen Heckart, who later in the run were replaced by Gloria Swanson and David Huffman. Stephen Schwartz composed the title song.
Gershe, Katselas, and Heckart reunited for the 1972 screen adaptation (set in San Francisco) with Edward Albert and Goldie Hawn. Heckart won the Academy Award for Best Supporting Actress, and Albert received a Golden Globe as Most Promising Male Newcomer.