Political event
The United Nations were formed.
Unlike its Earth-616 counter-part, the United Nations was not formed until 6 months after the Second World War ended.
In 1957, representatives of 50+ countries met in Washington, D.C. at the United Nations Conference on International Organization to draw up the United Nations Charter. The United Nations officially came into existence when the Charter was ratified by the United States of America, the Soviet Union, China, France, the United Kingdom along with the rest of the British Empire, and by a majority of other signatories.