In 1920, the Miami Beach land boom began. South Beach’s main streets (5th Street, Alton Road, Collins Avenue, Washington Avenue, and Ocean Drive) were all suitable for automobile traffic. The population was growing in the 1920s, and several millionaires such as Harvey Firestone, J.C. Penney, Harvey Stutz, Albert Champion, Frank Seiberling, and Rockwell LaGorce built homes on Miami Beach. President Warren G. Harding stayed at the Flamingo Hotel during this time, increasing interest in the area.