Genres evolve over time due to cultural and historical changes. In the 1940s-1950s, the lone Western hero was popular, but shows in the 1960s-1970s like Rawhide and Bonanza featured groups of heroes reflecting the modern workplace. As interest in crime and espionage rose in the 1970s-1980s, the Western was replaced by police/detective and spy genres. Audiences also seek certain genres that relate to the fears or realities of their time. During the Great Depression, people turned to romantic comedies as an escape from hardship.