John Adams was one of the Founding Fathers of the United States of America. A street in Florida was named after him, and the Eleventh Doctor realised that the little girl trapped inside a NASA spacesuit was located nearby.
According to the Eleventh Doctor, he was a lovely fellow. The Doctor stated that out of the three founding fathers he mentioned on an occasion — Hamilton, Jefferson and Adams — two fancied him. (TV: The Impossible Astronaut)