The U.S. Constitution owes a huge debt to ancient Rome. The Founding Fathers were well-versed in Greek and Roman History. Leaders like Thomas Jefferson and James Madison read the historian Polybius, who laid out one of the clearest descriptions of the Roman Republic’s constitution, where representatives of various factions and social classes checked the power of the elites and the power of the mob. It’s not surprising that in the United States’ nascent years, comparisons to ancient Rome were common. And to this day, Rome, whose 482-year-long Republic, bookended by several hundred years of monarchy and 1,500 years of imperial rule, is still the longest the world has seen.