I don't understand why you think William Henry Harrison was assassinated? W.H.H died in 1841. In 1841, Harrison became ill after catching a cold. Now, since medicine for certain cases wasn't advanced enough at that time, it was a common misconception that falling ill to a cold was caused by bad weather, and in his case, it was bad weather that happened during his inauguration. However, Harrison's illness did not arise until more than three weeks after the event. His cold became worse, rapidly turning into pneumonia and pleurisy, he was trying to get rest in the White House, but could not find a quiet room because of the steady crowd of office seekers, and his very busy social schedule did not give him time to rest.

Harrison's doctors attempted several cures, such as applying opium, castor oil, leeches, and Virginia snakeweed, but the treatments just made him worse.

He died nine days after becoming ill at 12:30 am on April 4, 1841. Harrison's doctor, Thomas Miller, diagnosed Harrison's cause of death as "pneumonia of the lower lobe of the right lung". But in 2014, a medical analysis concluded that he actually died of enteric fever. The authors based their findings on the president's symptoms and the close proximity of the White House to a dumping ground for sewage and human waste.