The story about how Harry Truman more or less singlehandedly decided that the United States would recognize Israel in May 1948 is well known. The State Department was unanimously against the idea, although at the last moment the Secretary of State did call the President and tell him that since he was determined to do the wrong thing, he, George Marshall, wouldn't oppose him in public. Yet the decision itself wasn't enough. In order for the United States to recognize a new country, someone had to ask them to do so, and no one in Tel Aviv had prepared for that. Clark Clifford, Truman's aide, called Eliyahu Epstein, a Jewish Agency official in Washington, and explained that there had to be an official request. Since neither Clifford nor Epstein knew what such a request might look like, Epstein was on his own. Ben Gurion had declared independence at 4pm Israel time, which was early morning in Washington, and the declaration would go into effect at midnight Israel time, on the first minute of May 15th, so there still were a few hours to figure it out.
Here's the result: A letter from Epstein to Truman, in English of course, in which he informed the president that a Jewish state had been declared, that it was called Israel, that it had a provisional government, and that it was requesting the recognition of the United States. At loss as to his own position, Epstein signed as an "agent of the provisional government".
And here's Truman's response. And notice that someone added the name of the new country, Israel, after the letter had already been typed. Originally it had simply said that the United States recognized a Jewish State.
The full story of the intigues and maneuvers leading to Truman's decision can be found in David McCullough's magesterial Truman from page 595 onwards, and this particular vignette is on pages 617-18.