The United Nations was officially established in 1945. The UN Charter entered into force on 24 October 1945, a date now observed annually as United Nations Day.
The organization was created near the end of the Second World War to replace the League of Nations and provide a forum for international cooperation. Representatives from 50 countries signed the Charter at the San Francisco Conference on 26 June 1945. Poland signed later, becoming the 51st original member state listed in the founding record.
The UN’s initial purposes included maintaining international peace and security, developing friendly relations among nations, and encouraging cooperation on economic, social, cultural, and humanitarian issues. Its headquarters is in New York City, though major UN bodies and offices operate elsewhere. The League of Nations was founded after the First World War in 1920, so it is a frequent source of date confusion.