Charles Francis Adams Sr. (August 18, 1807 – November 21, 1886) was an American historical editor, writer, politician, and diplomat. He was a son of President John Quincy Adams and grandson of President John Adams, about whom he wrote a major biography. Adams served two terms in the Massachusetts State Senate before running unsuccessfully as vice-presidential candidate for the Free Soil Party in the election of 1848 on a ticket with former president Martin Van Buren. During the Civil War, Adams served as the United States Minister to the United Kingdom under Abraham Lincoln, where he played a key role in keeping the British government neutral and not diplomatically recognizing the Confederacy. Adams became an overseer of Harvard University and built Adams National Historical Park, a library in Quincy, Massachusetts honoring his father.