San Francisco Bay Area a primary embarkation point for American forces. In 1945, the United Nations Charter was signed in San Francisco, establishing the United Nations, and in 1951, the Treaty of San Francisco officially ended the U.S.'s war with Japan. Since then, the Bay Area has experienced numerous political, cultural and artistic movements, developing unique local genres in music and art and establishing itself as a hotbed of progressive politics. Economically, the post-war Bay Area saw huge growth in the financial and technology industries, creating a vibrant and diverse economy with a gross domestic product of over $800 billion, and home to the
International Civil Aviation Organization convention, held in London in 1912 allocated the first radio callsigns for use by aircraft. ICAN continued to operate until 1945. Fifty-two countries signed the Chicago Convention on International Civil Aviation, also known as the Chicago Convention, in Chicago, Illinois, on 7 December 1944. Under its terms, a Provisional International Civil Aviation Organization (PICAO) was to be established, to be replaced in turn by a permanent organization when 26 countries ratified the convention. Accordingly, PICAO began operating on 6 June 1945, replacing ICAN. The 26th country ratified the Convention on 5 March 1947 and, consequently PICAO was disestablished on 4