The Founders were probably aware of that possibility since I believe Aristotle wrote how all the Greeks only lived in city-states in his Politics.

There were the necessities of self-defence; when war was almost the constant state of man, and nations were not yet organized, the country population could not extend very far from the city which protected them. What had been the fact thus became the principle. To the Greek the cities of Assyria or of Egypt, built in vast plains, seemed to have a monstrous and unmeaning greatness. The Greek races had quickly become diversified by circumstances into lesser tribes, and the configuration of the country tended to maintain and strengthen the subdivisions. A distinct and peculiar life was stamped upon each of them. The city soon became all in all; the country nothing.

—Aristotle, Politics, Volume I. Book VII. Chapter IV. Paragraph III. translated by Bemjamin Jowett, Oxford, 1885

I believe Thomas Jefferson of Virginia desired America to be comprised of rural Farmers, organized into shires, or counties, that is, towns of around a hundred just as in England, but I possess none of that Father's scripture as proof, unfortunately.