John Quincy Adams (#6)

John Quincy Adams (1767–1848) was arguably the most experienced man ever to enter the White House. The son of President John Adams, he had served as a diplomat in Europe from childhood, becoming fluent in multiple languages and serving as ambassador to Russia, Prussia, and the Netherlands before becoming Secretary of State under James Monroe. In that role, he was the primary architect of the Monroe Doctrine.

His presidency (1825–1829) was won through the House of Representatives after no candidate secured an Electoral College majority in the 1824 election — a process Andrew Jackson called a "corrupt bargain." Adams proposed ambitious national infrastructure and education programmes, but a hostile Congress blocked most of them. After losing to Jackson in 1828, Adams did something no former president had done: he ran for Congress, serving 17 distinguished years in the House of Representatives. He argued the Amistad case before the Supreme Court at age 73, successfully securing the freedom of enslaved Africans. He collapsed on the House floor in 1848 and died two days later.