William Henry Harrison
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 it was outdone in 1981 by Ronald Reagan who assumed the presidency at the age of 69. He was the last president to be born before the United States Declaration of Independence.