In April 1945, as World War II was coming to a close, representatives of 50 war-weary countries gathered in San Francisco, Calif., for the United Nations Conference on International Organization. For two months, the group worked on drafting and then signing the U.N. Charter, creating the United Nations, an international organization that all hoped would help prevent another world war. The charter was ratified by China, France, the Soviet Union, the United Kingdom, the U.S., and other nations, and the U.N. got off the ground officially on Oct. 24, 1945.