The United Nations Charter was signed by 50 nations in San Francisco on 26 June, 1945. On 6 July, the same year, Nicaragua became the 1st nation to ratify the Charter.
US Senate endorsed United Nations Charter 89-2 on 28 July, and President Harry Truman signed it on 28 August, 1945.
The United Nations Charter finally came into effect of 24 October, 1945.
The ratification was completed on 31 December, 1945.
We the peoples of the United Nations determined
– to save succeeding generations from the scourge of war, which twice in our lifetime has brought untold sorrow to mankind, and
– to reaffirm faith in fundamental human rights, in the dignity and worth of the human person, in the equal rights of men and women and of nations large and small, and
– to establish conditions under which justice and respect for the obligations arising from treaties and other sources of international law can be maintained, and
– to promote social progress and better standards of life in larger freedom,
And for these ends
– to practice tolerance and live together in peace with one another as good neighbours, and
– to unite our strength to maintain international peace and security, and
– to ensure, by the acceptance of principles and the institution of methods, that armed force shall not be used, save in the common interest, and
– to employ international machinery for the promotion of the economic and social advancement of all peoples,
Have resolved to combine our efforts to accomplish these aims
– Accordingly, our respective Governments, through representatives assembled in the city of San Francisco, who have exhibited their full powers found to be in good and due form, have agreed to the present Charter of the United Nations and do hereby establish an international organization to be known as the United Nations.