May 14, 1948
THIS GOVERNMENT has been informed that a Jewish state has been proclaimed in Palestine, and recognition has been requested by the provisional government thereof.
The United States recognizes the provisional government as the de facto authority of the new State of Israel.
Harry S Truman, Statement by the President Announcing Recognition of the State of Israel Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/232257