On 23 December 1783, in the Maryland State House at Annapolis, George Washington stood before the Confederation Congress and resigned as commander in chief of the Continental Army. The war was over. The last British troops had left New York. He still held the only army that mattered.
He did not keep it. He read a short address, offered his commission, and took his leave of public employment. The words are in the National Archives: he had finished the work assigned to him. He went home to Mount Vernon for Christmas.
Kings do not do this. Party armies do not do this. The American design begins here: the sword answers to a civilian Congress, and the man who could have been a Caesar chose to be a citizen. He would later take the presidency under a written Constitution — and leave that too.