John Tyler (1790-1862) became the tenth president of the United States while serving as vice president to William Henry Harrison, who died in office.

Tyler was born on March 29, 1790, at Greenway, his family’s plantation in Charles County, Virginia. His political career started early, as he was elected to the Virginia legislature at age 21. From 1817 to 1821, he was a member of the House of Representatives and was elected to Congress as a member of the Democratic-Republicans, the party that was founded in the early 1790s by Thomas Jefferson and James Madison.

In 1813, he married Letitia Christian and the couple had eight children. However, in 1839, Letitia suffered a stroke which left her partially paralyzed.

Tyler believed in states’ rights and strictly following the Constitution, instead of granting more power to the federal government. He served as the governor of Virginia from 1825 to 1827 and delivered the official eulogy for Jefferson, who died on July 4, 1826.

While serving in the U.S. Senate, Tyler started disagreeing with the policies of President Andrew Jackson and later became affiliated with the Whig Party, the opposition to Jackson. The Whigs selected Harrison and Tyler on the ticket to run for president and vice president in 1840. Harrison perished after only one month in office due to pneumonia and Tyler became the sitting president. Because the first lady could not handle her duties due to her stroke, her daughter-in-law, Priscilla Cooper Tyler, a former actress, assumed the role of White House hostess. Two years later, in 1842, Letitia suffered a second stroke and died at the age of 51.

Tyler became the first president to marry while in office when he wed Julia Gardiner in 1844. The couple had seven children, giving him a total of 15 and the distinction of fathering more children than any other U.S. president.

At first, no one was certain on how to handle Harrison’s death and whether Tyler should remain in his position as vice or take over the office since the Constitution was unclear on that matter. At 51 years old, he was sworn into office on April 6 and dubbed “His Accidency.” It wasn’t until 1967 that the 25th Amendment to the Constitution was ratified, stating that the vice president will take the presidential office if the current president dies or resigns.

After retiring from office, Tyler returned to his plantation and voted in favor of Virginia seceding from the Union. He was elected to the Confederate House of Representatives but died at the age of 71 on January 18, 1862 before he could take his seat. President Abraham Lincoln and the government did not acknowledge Tyler’s death because he was seen as a traitor to the union.