The early currency of the United States did not exhibit faces of presidents, as is the custom now; although today, by law, only the portrait of a deceased individual may appear on United States currency. In fact, the newly formed government was against having portraits of leaders on the currency, a practice compared to the policies of European monarchs. The currency as we know it today did not get the faces they currently have until after the early 20th century; before that "heads" side of coinage used profile faces and striding, seated, and standing figures from Greek and Roman mythology and composite Native Americans. The last coins to be converted to profiles of historic Americans were the dime (1946) and the Dollar (1971).
What was the last coin to be converted to the modern day style of having mythology on the face?