Which of the following Presidents wasn't assassinated?

Warren Harding, the 29th President of The United States(1921-1923), died in office on August 2, 1923 of a cerebral hemorrhage. While a popular president, his reputation later suffered significantly when several scandals were exposed about his administration.The Tea Pot Dome was the greatest. Harding's Secretary of The Interior, Albert Bacon Fall, had received $400,000 for drilling rights on federal land in Wyoming. Other scandals perpetrated by his associates, dubbed The Ohio Gang, seriously undermined Harding's administration. His handling of the scandals also hurt his administration. When he discovered Charles Forbes, Director of The Veterans Administration, was awarding contracts for kickbacks, he demanded his resignation. But allowed him to flee to Europe to avoid further damage.

Harding had numerous affairs, although not publicly known, while in office, this also hurt his reputation in later years. The most infamous being with Nan Britton, thirty one years his junior, with whom he had a daughter.