Why is democracy the political system of the us government

Democracy was present in the USA since the colony time in which there were three social classes: the gentry that were the rich people who were able to vote, then there were the middle class and the poor that were not entitled to vote. The first president after the revolutionary war was George Washington who was elected by 69 members of the electorate college. It  means that at that time there was an electoral college and democracy started there.

first, the romans stayed isolated because they had to defend their own territories from neighboring cities that were harassing them, like the etruscans. second, once the romans managed to defeat their neighbors, and started to expand their territory, they started to build roads and bridges. finally, now that the romans have covered their territory with roads functioning as highways, they could mobilize their legions faster to assemble larger military units in a specific place.