He was elected president in 1840, and took the oath of office on March 4, 1841. His inauguration speech lasted an hour and forty minutes. William Henry Harrison caught a serious case of pneumonia, and on April 4 that same year he died. He was the first President to die in office. Harrison was the oldest president to take office at , until 1981 when Ronald Reagan surpassed him who in turn was outdone in 2021 by Joe Biden who assumed the presidency at the age of 78. He was the last president to be born before the United States Declaration of Independence.