Complex sentence: In March 1939, Hitchcock moved to Hollywood to begin his contract with David O. Selznick, so "Jamaica Inn" was his last British picture, as well as one of his most successful.
Split into simpler sentences: In March 1939, Hitchcock moved to Hollywood to begin his contract with David O. Selznick. Thus, as it was said in the beginning of this article, "Jamaica Inn" was his last British picture, as well as one of his most successful.