The founding fathers of the United States were products of a classical education, and they used the Greek and Roman classics as republican models and classical virtues. In their writings, the founders frequently associated liberty and republicanism with the ancient commonwealths. John Adams spoke on three separate occasions of the need to reflect on the past republics of Greece and Rome. The founding fathers used many ideas from the third century (B.C.) Roman Republic in the formation of the U.S. republican government. In the Federalist Papers, Madison redefined a republic as a government based on popular sovereignty, with government authority directly or indirectly residing with the people, and administered by elected representatives holding their office for a limited period or during good behavior. The founders also wanted to avoid the problems that these ancient governments encountered. They believed that, with the addition of separation of powers, checks and balances, an independent judiciary, and representative legislatures, the republican model could be adapted for the new nation. Hamilton used the example of divided sovereignty in the Roman Republic as an argument for the workability of a federal system. Opponents criticized the use of classical models during the battle for ratification. Nonetheless, the founders were strongly influenced by their study of the classical republics and built the new government on their foundations. (SM)