The United Nations (UN) was officially established on October 24, 1945, following the conclusion of World War II. Its primary mission was to prevent future global conflicts, replacing the failed League of Nations. Representatives from 50 countries met in San Francisco to draft the UN Charter, which outlined the organization's goals: maintaining international peace and security, promoting human rights, and fostering social and economic development. The UN was structured with the General Assembly for all members and a Security Council with five permanent members (U.S., UK, USSR, France, and China) holding veto power. While the UN has faced criticism for its inability to stop certain conflicts during the Cold War, it has played a vital role in international law, global health initiatives through the WHO, and the provision of humanitarian aid through agencies like UNICEF.