WereMaurice Elvey and Arthur Lubin both from the USA?
Maurice Elvey Maurice Elvey (11 November 1887 – 28 August 1967) was the most prolific film director in British history. He directed nearly 200 films between 1913 and 1957. During the silent film era he directed as many as twenty films per year. He also produced more than fifty films - his own as well as films directed by others.
Samuel Hoffenstein Samuel "Sam" Hoffenstein (October 8, 1890 - October 6, 1947) was a screenwriter and a musical composer. Born in Russia, he emigrated to the United States and began a career in New York City as a newspaper writer and in the entertainment business. In 1931 he moved to Los Angeles, where he lived for the rest of his life and where he wrote the scripts for over thirty movies. These movies included "Dr. Jekyll and Mr. Hyde" (1931), "The Miracle Man" (1932), "Phantom of the Opera" (1943), "The Wizard of Oz" (1939), "Tales of Manhattan" (1942), "Flesh and Fantasy" (1943), "Laura" (1944), and Ernst Lubitsch's "Cluny Brown" (1946).