Participation in fly fishing peaked in the early 1920s in the eastern states of Maine and Vermont and in the Midwest in the spring creeks of Wisconsin. Along with deep sea fishing, Ernest Hemingway did much to popularize fly fishing through his works of fiction, including The Sun Also Rises. It was the development of inexpensive fiberglass rods, synthetic fly lines, and monofilament leaders, however, in the early 1950s, that revived the popularity of fly fishing, especially in the United States. In recent years, interest in fly fishing has surged as baby boomers have discovered the sport. Movies such as Robert Redford’s film A River Runs Through It, starring Brad Pitt, cable fishing shows, and the emergence of a competitive fly casting circuit have also added to the sport’s visibility.