The United States is a culturally diverse nation, home to a wide variety of ethnic groups, traditions, and values.Since the early twentieth century, the U.S. film industry has largely been based in and around Hollywood, California. American screen actors like John Wayne and Marilyn Monroe have become iconic figures, while producer/entrepreneur Walt Disney was a leader in both animated film and movie merchandising. The major film studios of Hollywood are the primary source of the most commercially successful movies in the world, such as Star Wars (1977) and Titanic (1997), and the products of Hollywood today dominate the global film industry. Americans are the heaviest television viewers in the world,and the average time spent in front of the screen continues to rise, hitting five hours a day in 2006. The rhythmic and lyrical styles of African American music have deeply influenced American music at large, distinguishing it from European traditions. Since the late nineteenth century, baseball has been regarded as the national sport; football, basketball, and ice hockey are the country's three other leading professional team sports. Soccer, though not a leading professional sport in the country, is played widely at the youth and amateur levels. Tennis and many outdoor sports are also popular.