John Tyler was another who rose to the office of the presidency following the death of his predecessor, on this occasion by the shortest-serving President in American history in William Henry Harrison. Harrison died of pneumonia just 32 days into office, meaning Tyler became the first ever President to replace a deceased predecessor. Tyler therefore became the 10th President, serving between 1841 and 1845. Due to the fact he was not elected to office but still served pretty much a full term, Tyler became known as "His Accidency" by his political opponents.