Answer: on June 26, 1945 50 countries signed the United Nations Charter and not too long after Poland also signed making a total of 51
ANSWER: A total of 51 original members (or founding members) joined that year; 50 of them signed the Charter at the United Nations Conference on International Organization in San Francisco on 26 June 1945, while Poland, which was not represented at the conference, signed it on 15 October 1945.
