The 6th President of the United States, John Quincy Adams, was accused of being a pimp.
Summary from Source
In Vindicating Andrew Jackson, Donald B. Cole describes the origin of the 1827 Jacksonian campaign slur that John Quincy Adams pimped for Tsar Alexander I of Russia while Adams served as United States Ambassador to that country between 1809 and 1814:Another, more ludicrous attack was the story relating to the czar of Russia. While Adams was minister to Russia, a young chambermaid on his staff wrote a letter in which she made some casual remarks about the czar. On being informed of the letter, the czar was so amused and curious that he asked to speak to her.
So during his next audience with the czar, Adams brought the woman in for a brief conversation. This humdrum story had no political appeal until it appeared in a short sketch of Jackson published by Isaac Hill in which Hill accused Adams of being a pimp who had procured a woman for the lascivious pleasure of the czar. Once the story appeared in the sketch, it spread throughout the Jackson press.