Who was unanimously elected the first president of the United States under the Constitution?

George Washington was unanimously elected the first president of the United States under the Constitution.

Washington received every electoral vote in the first presidential election, held in 1789. John Adams received the second-highest total and therefore became vice president under the original constitutional election system.

Washington had been widely respected as commander in chief of the Continental Army during the Revolutionary War. His leadership and decision to surrender military power after the war helped make him an acceptable national figure to supporters of both a stronger union and greater state authority.

He took the presidential oath of office on April 30, 1789, in New York City. Washington's unanimous election was unique in American presidential history; later presidents won electoral majorities or pluralities rather than every electoral vote.