The Story of Alexander Graham Bell (1939) Don Ameche, Loretta Young, Henry Fonda

Alexander Graham Bell falls in love with deaf girl Mabel Hubbard while teaching the deaf and trying to invent means for telegraphing the human voice. She urges him to put off thoughts of marriage until his experiments are complete. He invents the telephone, marries and becomes rich and famous, though his happiness is threatened when a rival company sets out to ruin him.