Harpo Marx York accent his entire life. According to those who personally knew him, Harpo's voice was much deeper than Groucho's, but it also sounded very similar to Chico's. His son, Bill, recalled that in private Harpo had a very deep and mature soft-spoken voice, but that he was "not verbose" like the other Marx brothers; Harpo preferred listening and learning from others. Harpo's final public appearance came on January 19, 1963 with singer/comedian Allan Sherman. Sherman burst into tears when Harpo announced his retirement from the entertainment business. Comedian Steve Allen, who was in the audience, remembered that Harpo spoke for
Biographies of Karl Marx (1925), Japanese (1930), Spanish (1932), and English (1935). Marx: Man and Fighter is a biography by Boris Nicolaievsky, first published in German in 1933. It was translated into English by Otto Mänchen-Helfen and published in 1936. Some subsequent English editions restore the notes, appendices, and bibliography omitted from the first English edition. Karl Marx: His Life and Environment is a 1939 biography of Karl Marx by Isaiah Berlin, in which Berlin argues that Marx's system of thought depends upon indefensible metaphysical presuppositions. Karl Marx: His Life and Thought is a 1973 biography of Karl Marx by political scientist David McLellan.