Which U S president had a middle name that was just a single letter? Correct
Harry S. Truman is the U.S. president who had a middle name with just a single letter, “S.” This distinguishes him from George Bush, Lyndon Johnson, and Dwight Eisenhower, who all had traditional middle names with more than one letter. Harry S. Truman, the 33rd President of the United States, famously used the initial “S” without a period as an homage to his grandfathers, whose names both had “S” as the middle initial. This unique naming convention sets Truman apart from the other presidents listed, making him the only one with a middle name consisting of just one letter.
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