Was the US the first non-monarchical government?

Answer 1

I hope this helps:

No. Although I cannot say that they are the first two non-monarchical governments (and one depends on your point of view), Israel and Rome developed some of the earliest 'Republics' in the world.

Israel's eldest 11 sons sold the youngest (and most favored of their father) Joseph to slavers who brought him to Egypt where he had many adventures and made a great name for himself. When famine struck, Israel's family moved to Egypt which still had food because of Joseph. They prospered for many generations because of the patronage of Joseph.

Then a pharaoh came to power who did not know Joseph (paraphrased) and he persecuted the Jews horribly. They were freed by Moses and left, but Moses did not become King. The only King the Jews claimed was God. Most governance at this time was prophecy of God, and orders from the assembly of the people and elders. In many ways the Jews were a Republic.

The Romans were a different matter. They were united by their first (and legendary) King Romulus. He established the Senate and the Patrician class (all of whom were descended from the original Senators). During interregnums (between kings) the Senate would convene to choose a new King.

Unlike most modern monarchies, the Roman Kings were not hereditary. So, the Senate chose several until finally the Senate and people of Rome became disenchanted with the idea of kings (due to the corruption of the last one) and drove him and monarchy from the city. Thus the Roman Republic was born. Note: the later Roman Emperors did everything in their power to avoid the stigma of monarchy even though that is what they were.

The Senate ruled from then until the Caesars stole power from them.

That's not the whole story, and may be inaccurate in some ways, but you should do more research if it's important to you.