Who was the only president who was a member of the Federalist Party?

While George Washington was sympathetic to Federalist views, he never actually joined the party, and remained unaffiliated for both of his presidential terms. John Adams, who succeeded Washington, was the only true Federalist president.

The Federalist party was the first American political party. They espoused a strong federal government, a loose interpretation of the constitution, and supported the idea of a national bank.

The party was overwhelmed by Jefferson's Democratic-Republican party in the early 1800's and slowly declined into the 1820's, when they disappeared from the American political scene. However, Chief Justice John Marshall, who shaped Supreme Court policy for decades, was a Federalist. So, in this regard at least, Federalist influence did continue until 1835.