Bolton returned to the US during the Second World War to write the librettos for "Walk With Music", "Hold On to Your Hats", "Jackpot" (with several contributors) and "Follow the Girls" (with Eddie Davis). Bolton's screen credits include "The Love Parade" (1929), "Ambassador Bill" (1931), "Waltzes from Vienna" (1934), "The Murder Man" (1935), "Angel" (1937), "Week-End at the Waldorf" (1945), "Ziegfeld Follies" (1945), "Till the Clouds Roll By" (1946), "Easter Parade" (1948) and the German adaptation of his play "Adorable Julia" (1962). In 1952, he moved away from musicals with an English adaptation of Marcelle Maurette's "Anastasia". His last book for Broadway was "Anya", a 1967 musical adaptation of "Anastasia" based on his adaptation and the 1956 film.