In 1945 , he became Minister of Foreign Relations , and in that capacity , represented Colombia at the Chapultepec Conference and the United Nations Conference on International Organization in San Francisco , which created the United Nations . But that same year , the Senate named designated him as Acting President , a position he occupied until 1946 , when Conservative Mariano Ospina Pérez was elected president . At only thirty-nine years-old , he became one of the youngest Acting Presidents in Colombian history . During his short year in office , the Greater Colombian Merchant Fleet was founded and the Constitutional Reform of 1945 completed
United Nations Conference on International Organization
United Nations Conference on International Organization
Alberto Lleras Camargo