Final answer:
George Washington concluded his oath of office by saying, "I do solemnly swear (or affirm) that I will faithfully execute the Office of President of the United States, and will to the best of my Ability, preserve, protect and defend the Constitution of the United States."
Step-by-step explanation:
George Washington concluded his oath of office by saying, "I do solemnly swear (or affirm) that I will faithfully execute the Office of President of the United States, and will to the best of my Ability, preserve, protect and defend the Constitution of the United States." This oath is outlined in Section 1 Clause 8 of the Constitution. After concluding the oath, New Yorker Robert Livingston, who administered the oath, proclaimed, "Long live George Washington, President of the United States."