See American Empire, Part 1 here.
Beginnings
How did Rome begin? One might as well ask, When does a tribe become a monarchy? When does a chief become a King? When building a new city from scratch, as the legendary Romulus and Remus did, the default state is to rule as a King. The Aeneid tells of a town pre-existing the formal foundation of Rome, Latium. We can also learn some from Plutarch via the second King of Rome, Numa Pompilius[1], that there were numerous other settlements surrounding Rome. So I believe it is sensible at least to say that the area around Rome was populated by settlements which were structured around a single ruler.
The United States, too, began as a Monarchy, though in a different form. The Monarchy already existed, but the territory was colonized by royal subjects. Looking past explicit comparisons of Aeneas with Columbus, A new people were formed out of some material that already existed. “Roman” was not distinct at it’s foundation, but as it grew aggressively the Sabines and Etruscans and Latins became one nation. The Britons, variously fleeing persecution or following the promises of wealth, found themselves far from home but still subject to the King.
Of Monarchs and Men
The Monarchies of early Rome and early USA are distinctly different. Rome was a non-hereditary monarchy, limited by the Senate. America began explicitly as sovereign subjects of the King, either directly or indirectly via joint stock companies. This gave both nations different starting points in terms of legal liberties. However, the reality of the frontier mitigates that somewhat. Far from any authority to enforce, the American colonies developed in a controlled and structured way, but free to experiment and with a dose of danger and lawlessness inherent in being far from direct enforcement. At the point of Rome’s foundation, it’s citizens were few and faced threats on all sides from the local cities. American colonists were few and faced threats on all sides from native Americans. The de facto conditions of their development are very similar.
The impact of this type of development cannot be understated. Early Romans and American colonists built by hand, from nothing, a safe place to live. They battled nature and fellow men; but by their blood, sweat, and tears, they built it. Americans could not credit a distant King for their survival–that was something they witnessed and achieved on their own. The first Roman liege-lord, Romulus, lived among them in their primitive nation. His presence strengthened their national identity rapidly. Americans begrudgingly retained their ties to home, recognizing the fruitful mutual relationship. The hand that fed was the Kings, but the fruits of their labors were all their own.
The Seeds of Republic
The seeds of republic were there from the inception of both societies. The Senate was a Roman institution from the earliest days of Rome and served to select the next King. Whenever men are given power, there will be those who crave more. Some senators would surely come to consider themselves more wise and just than the prospective Kings they had to choose from. So to in America, where the King was not an absolute monarch in the traditional sense, but was limited in the post-magna-carta structure of a Constitutional Monarchy. The idea of a limited legislature, and in turn of a singular document establishing the rules of conduct of the government, existed from the earliest days of the American colonies and surely only grew in their imaginations as they labored far from the reach of their Monarch.
In both cases, the Monarchy was overthrown by violence. Lucius Tarquinius Superbus was the seventh king of the Roman Monarchy, and was considered particularly cruel. He had some senators put to death and refused to replace them. The senate, seeing their size and authority thus diminished, seized on the indefensible crime of the Kings son raping a woman and overthrew the monarch. When the Liege and Legislature feud, one will overthrow the other.
In America, the escalating financial burdens borne by the colony to finance wars they were not involved in increased the unpopularity of the monarch. The trigger was the tax on tea, resulting in the famous ‘Boston Tea Party’, the subsequent Declaration of independence, and bloody revolution.
[1] Plutarch’s Lives is a study in duality. Numa Pompilius was compared to Lycurgus, the Lawgiver of Sparta and founder of Sparta as we know it. Numa Pompilius was the second King of Rome, and founded many of the customs that lasted the duration of the Roman nation.
See American Empire, Part 3 here.
Times-Dispatch of Vichy Earth 