On March 4, 1930, former U.S. President Calvin Coolidge dedicated a dam on the Gila River named in his honor. However, the state had just been through a long drought, and the reservoir which was supposed to be behind the dam was virtually dry. The humorist Will Rogers, who was on hand as a guest speaker joked, If that was my lake, I'd mow it. Phoenix's population had more than doubled during the 1920s, and now stood at 48,118. It was also during the 1930s that Phoenix and its surrounding area began to be called The Valley of the Sun, which was an advertising slogan invented to boost tourism.