William was the ninth President of the United States (1841), an American military officer and politician, and the last president born as a British subject. He was also the first president to die in office. He was 68 years, 23 days old when inaugurated, the oldest president to take office until Ronald Reagan in 1981. Harrison died on his 32nd day in office[a] of complications from pneumonia, serving the shortest tenure in United States presidential history. His death sparked a brief constitutional crisis, but its resolution left unsettled many questions following the presidential line of succession in regard to Constitution until the passage of the 25th Amendment in 1967. He was the grandfather of Benjamin Harrison, who served as the 23rd President from 1889 to 1893.
Before election as president, Harrison served as the first territorial congressional delegate from the Northwest Territory, as governor of the Indiana Territory, and later as a U.S. representative and senator from Ohio. He originally gained national fame for leading U.S. forces against American Indians at the Battle of Tippecanoe in 1811, where he earned the nickname «Tippecanoe» (or «Old Tippecanoe»). As a general in the subsequent War of 1812, his most notable action was in the Battle of the Thames in 1813. This battle resulted in the death of Tecumseh and the dissolution of the Indian coalition which he led.