John Quincy Adams was an American statesman, diplomat, lawyer, and diarist who served as the sixth president of the United States, from 1825 to 1829.

Adams served as Secretary of State throughout James Monroe's eight-year presidency, from 1817 to 1825. In that role, he negotiated the Adams-Onís Treaty, which provided for the American acquisition of Florida. He also helped formulate the Monroe Doctrine, which became a key tenet of U.S. foreign policy.

Born in what is now Quincy, Massachusetts (then part of the town of Braintree), Adams spent much of his youth in Europe, where his father served as a diplomat.

In 1809, he argued before the Supreme Court of the United States in the case of Fletcher v. Peck, and the Supreme Court ultimately agreed with Adams' argument that the Constitution's Contract Clause prevented the state of Georgia from invalidating a land sale to out-of-state companies.

In February 1811, Adams was nominated by President James Madison as an Associate Justice of the United States Supreme Court. The nomination was unanimously confirmed by the Senate, but Adams declined the seat, preferring a career in politics and diplomacy. The seat was later filled by Joseph Story.

Initially a Federalist like his father, Adams won election to the presidency as a member of the Democratic-Republican Party, and in the mid-1830s became affiliated with the Whig Party.

Adams was inaugurated on March 4, 1825. He took the oath of office on a book of constitutional law, instead of the more traditional Bible.

Adams spent the winter of 1795-96 in London, where he met Louisa Catherine Johnson, the second daughter of American merchant Joshua Johnson. In April 1796, Louisa accepted Adams's proposal of marriage. Shortly after the wedding, Joshua Johnson fled England to escape his creditors, and Adams did not receive the dowry that Johnson had promised him, but Adams noted in his diary that he had no regrets about marrying Louisa.

The collapse of the Federalist Party lead to a four-way presidential race between members of the Democratic-Republican Party in which no candidate obtained the necessary majority of electoral votes to win. Under the terms of the 12th Amendment, the House held a runoff vote on December 1, 1824, in which Adams emerged victorious after securing the endorsement of Henry Clay, one of the other three candidates. After the election, supporters of the war hero Andrew Jackson claimed that Adams and Clay had reached a "corrupt bargain" whereby Adams promised Clay the position of Secretary of State in return for Clay's support.

In 1824-25, the Revolutionary War hero the Marquis de Lafayette made a tour of America. During this tour, he was given many gifts, including a live alligator. When he visited the White House, he re-gifted the alligator to President Adams, who kept it in a tub in the East Room of the White House for a few months, supposedly claiming that he enjoyed watching "the spectacle of guests fleeing from the room in terror."