Louise made her film debut in 1958 in "God's Little Acre". That same year, the National Art Council named her the "World's Most Beautiful Redhead." The next year, she starred in "Day of the Outlaw" with Robert Ryan. She became a leading lady for stars such as Robert Taylor and Richard Widmark, often playing somber roles. She turned down roles in the films of "Li'l Abner" and "Operation Petticoat", taking roles on Broadway and in Italian cinema. Among her Italian film credits were The Siege of Syracuse directed by Pietro Francisci, and "Garibaldi" (1960), directed by Roberto Rossellini that concerned Garibaldi's efforts to unify the Italian states in 1860. Louise returned to the United States, began studying with Lee Strasberg, and became a member of the Actors Studio. In 1962, she guest-starred on the situation comedy "The Real McCoys", portraying a country girl from West Virginia in the episode "Grandpa Pygmalion". She appeared with Bob Denver two years later in the beach party film "For Those Who Think Young".