Article Two of the new U.S. Constitution specified that each state appoint a  presidential electors equal to the “number of Senators and Representatives to which the state may be entitled in Congress.”

Each elector would vote for two people, at least one of whom did not live in their state. The individual receiving the greatest number of votes would be elected President, and the next-in-line, Vice President.
The first election was set for February 4, 1789.

Between December 15, 1788 and January 10, 1789, electors were chosen in each of the states, but New York failed to choose its eight electors in time for the vote, two electors each from Virginia and Maryland were delayed by weather, and North Carolina and Rhode Island, which would have had seven and three electors respectively, had not yet ratified the Constitution and so could not vote.

So on February 4, 1789 the remaining 69 electors of the Electoral College gathered to cast their votes.

George Washington was the favorite son of the largest state and had served as Commander-in-Chief of the Continental Army and President of the 1787 Constitutional Convention in Philadelphia. When the votes were counted Washington was unanimously elected the first President of the United States with all 69 electoral votes. No other president since has come into office with anything close to such a universal mandate.

John Adams, who had served as the first U.S. ambassador to Great Britain, finished second with 34 electoral votes and became the first Vice President of the United States.

John Jay came in third with 9 votes, Robert Harrison and John Rutledge each received 6, John Hancock got 4, and George Clinton 3. Five other candidates split the remaining seven votes.

Upon hearing the news of his decisive election, Washington reluctantly returned from Mount Vernon to New York “in obedience to the public summons” to assume his new responsibilities, explaining that “the voice of my Country called me.”