Until President Ronald Reagan took office at the age of 69 in 1981, the oldest President in American History was President William Henry Harrison, the ninth President of the United States. Harrison was also the briefest President in American History. He died after only 30 days in office. His death, which was the first for an incumbent American President created a Constitutional crisis which was not fully resolved until the ratification of the 25th Amendment in 1967.
During the campaign of 1840, Harrison faced the incumbent Martin Van Buren for President. Van Buren's supporters tried to paint Harrison as elderly, provincial, and out-of-touch with the American people. Their attempts backfired, however, when Harrison and his supporters played up his supposed connection to the common man and painted Van Buren as an aristocrat. The Harrison campaign also made much of Harrison's military service in the wars against the Indians and in the War of 1812 using the slogan, "Tippecanoe and Tyler Too." This strategy worked. Although Harrison had only a slight lead in the popular vote, he won a landslide victory in the electoral college and became the 9th President of the United States.
At 68 years old he was the oldest President to that point in American history and was derided by some as a "Granny." Therefore, he still felt that he had to prove that he was the robust hero of Tippecanoe. That March 4th happened to be an extremely cold and wet day, but Harrison went without his overcoat to prove that he was not a frail old man. Standing in the rain, the delivered the longest inaugural address in American history. The speech lasted almost two hours after which he rode through the streets in the inaugural parade. Again, he did not wear an overcoat. Unsurprisingly, he caught cold which eventually developed into pneumonia and pleurisy.
Although the weather itself did not kill Harrison, it probably exacerbated a viral condition he had contracted. In his weakened conditioned, he needed rest for his body to fight the virus. In the immediate aftermath of his election, however, he was inundated by requests for audiences, so he allowed little time for rest. Without rest, his body could not fight the virus and he slowly succumbed to it. Eventually, doctors tried to cure him with opium, castor oil, Virginia snakeweed, but they were unsuccessful. Exactly one month after his inauguration, he died from pneumonia, jaundice, and blood poisoning.
Upon his death, Harrison was succeeded by his Vice-President John Tyler. Since no President had died in office before, no one was quite sure how Presidential succession worked. The Constitution stipulated that the Vice-President should become the new President, but it was not clear if the Vice-President should be considered a "real" President or if he only acted as President. The Tyler administration made it clear that Vice-Presidents who became President after the death of the elected President should be treated as legitimate Presidents. That question was not decided once and for all, however, until the 25th Amendment was ratified in 1967.
