Popular culture in the 1920s was characterized by innovation in film, visual art and architecture, radio, music, dance, fashion, literature, intellectual movements, the flapper, automobiles, nightclubs, movies, and jazz. Life moved fast as a new sense of prosperity and freedom emerged at the end of World War I. Products were manufactured in mass-produced packaging. Billboards popped up all over the cities. Crossword puzzles, board games, and marathon dancing became the new "crazes." New technology became available for ordinary citizens, and because of this, the era also came to be known as the "Machine Age." The movie industry skyrocketed in the 1920s with the growth of Hollywood and downtown movie theaters. Silent films gradually came to be replaced by "talkies" in the late '20s. Flappers were also becoming immensely popular, by changing the way society viewed young women forever. Radio in the 1920s "knitted the nation together." It started as local stations, but as technology improved, national stations became more and more popular. These national programs were sponsored by manufacturers and distributors of brand-name products. Stations broadcasted everything from news and music to politics and news. "Amos 'n' Andy" was a popular comedy program of the time.