President Andrew Jackson’s spoils system was an anti-corruption purge, not unlike Mr. Trump’s own. President William McKinley’s protectionist stance was also downright Trumpian. Oh, and the Unabomber, too, evidently has a link to the 47th president, by his telling: His uncle once taught the notorious terrorist. Since retaking office, Mr. Trump has spun many historical yarns that stretch the truth, strain credulity or are downright false.