The second president of the United States, John Adams, jots down his interpretation of the Pythagorean theorem.
The third president, Thomas Jefferson, sketched out his vision of a garden.
John Quincy Adams
John Quincy Adams, the sixth president (and son of the second), was known to be an intellectual. This is his interpretation of the stars.
Andrew Jackson, the seventh President of the United States from 1829 until 1837, lead the country to victory in the War of 1812 as a major general. This is his rendition of an alligator.
William Henry Harrison
The ninth president, William Henry Harrison, scribbled out a house.
This is a doodle done by James Garfield, the 12th president of the United States.
Ulysses S. Grant
The 18th president, Ulysses S. Grant, won the Civil War for the Union. This doodle refers to the march to the sea made by Union Major General William Tecumseh Sherman which was the beginning of the end for the Confederate Army.
Warren G. Harding
President Warren G. Harding was elected in 1920, two years after the bloody First World War. He died two years after assuming office. This is his drawing of an ostrich.
Calvin Coolidge assumed the presidency after Harding died in 1923. This is his very abstract lines-and-dots doodle.
Experts say that the 31st president, Herbert Hoover, was one of the most prolific doodlers ever to live in the White House. An engineer, his drawings have a very mechanical look.
John F. Kennedy
The United States increased its involvement in Vietnam during the presidency of John F. Kennedy. Judging by this doodle, it was obviously something he thought about. By the time he was killed in November 1963, there were thousands of troops in the country.
Lyndon B. Johnson
President Lyndon Johnson took control of the White House after Kennedy was assassinated. Under his leadership, the Vietnam war escalated. This is a drawing of a "hybrid creature."
Experts say that the 37th president, Richard Nixon, made somewhat boring doodles: a lot of triangles and squares.
President Ronald Reagan, who held office from 1981 to 1989, was one of the most active doodlers. He often drew horses, cowboys, athletes, and his wife, Nancy.