When did William Henry Harrison become president?

William Henry Harrison took the oath of office of March 4th, 1841, making him the ninth President of the United States. He and his running mate, John Tyler, defeated Martin Van Buren in the 1840 election. Harrison became the first Whig president and at the age of 68 years 23 days, he was the oldest president. He remained the oldest until Ronald Reagan took that title in 1981 at 69 years old, and later Donald Trump became the oldest president at 70. Harrison also gave the longest inaugural speech in history, which lasted two hours, on a day that was cold and rainy. Another fact is that he served the shortest term as president. Thirty-one days into his term, he died. At the time, doctors said his death was due to pneumonia from his inauguration, but later medical research suggests a contaminated water system in the white house may have caused typhoid fever.