The wise among them wrote treatises on the remedies they proposed.

The wisest went to school of experience and sought in history how confederations and other political unions had fared.
Washington wrote for his own use an account of the classical constitutions of Greece and Rome and of the more modern states; of the Amphictyonic Council among the ancient, and the Helvetic, Belgic, and Germanic among the more recent.

John Adams devoted two massive volumes to an account of the medieval Italian republics.

James Madison studied the Achaian League and other ancient combinations.

There were many other men less eminent than these--there was a Peletiah Webster, for instance.
Washington viewed the situation as a pessimist.