Hiram Warren Johnson (September 2, 1866 – August 6, 1945) was initially a leading American progressive and then a Liberal Isolationist Republican politician from California. He served as the 23rd Governor of California from 1911 to 1917 and as a United States Senator from 1917 to 1945. He was also Theodore Roosevelt’s running mate in the 1912 presidential election on the Progressive (also known as the “Bull Moose”) ticket.