John Adams (1735-1826) was elected president in 1796 and took office (became president) on March 4, 1797. He served only a single term as President, and was succeeded by Thomas Jefferson on March 4, 1801.
Adams had been Vice President for two terms under George Washington, from 1789 to 1797.
John Adams was the first President to serve 4 years.
He was the second President of USA.
Yes, James Madison did help write the Constitution of the United States of America!