Why old Ben, the quintessential American? Because I'll give him credit for creating the Post Office system. He didn't, actually, but was the dominant figure in its early days. The post office was critical in the evolution of America. Think about the situation in 1700--most transportation was by ship between a port in the colonies and a port in Great Britain. That meant communication between colonies was very limited and there was little chance for them to develop a consciousness of themselves as "American".
By 1760 there were roads (or at least a road) connecting the colonies and reasonable mail service. That mail service required setting up routes, hiring postmasters, setting rules and coordinating the whole effort. That was Franklin.
Besides, he was the most interesting American before Lincoln. Our high schools could spend a semester just discussing Ben, his writings, and works. The author of "Fart Proudly" surely can connect with today's teens.