William Henry Harrison (February 9, 1773 – April 4, 1841) was an American military officer and politician who served as the ninth president of the United States in 1841. He died of typhoid, pneumonia or paratyphoid fever 31 days into his term (the shortest tenure), becoming the first president to die in office. His death sparked a brief constitutional crisis regarding succession to the presidency because the Constitution was unclear as to whether Vice President John Tyler should assume the office of president or merely execute the duties of the vacant office. Tyler claimed a constitutional mandate to carry out the full powers and duties of the presidency and took the presidential oath of office, setting an important precedent for an orderly transfer of presidential power when a president leaves the office.[1] Harrison was a son of Founding Father Benjamin Harrison V and the paternal grandfather of Benjamin Harrison, the 23rd president of the United States. He was the last president born as a British subject in the Thirteen Colonies before the start of the Revolutionary War in 1775. During his early military career, he participated in the 1794 Battle of Fallen Timbers, an American military victory that effectively ended the Northwest Indian War. Later, he led a military force against Tecumseh's Confederacy at the Battle of Tippecanoe in 1811,[2] where he earned the nickname "Old Tippecanoe". He was promoted to major general in the Army in the War of 1812, and in 1813 led American infantry and cavalry at the Battle of the Thames in Upper Canada. Less