When Walt Disney World opened its doors on October 1, 1971 and introduced the second generation of Disney theme park entertainment, no one could have imagined how popular this worldwide destination would become. Covering 40 square miles, Walt Disney World Resort is about the size of San Francisco or two Manhattan islands. Carrie Stahl went down in Disney history as the park’s 150-millionth guest in 1983, just one year after the opening of Walt’s dream park, Epcot.