Final answer:
The civilization that had the most influence on American government is ancient Greece, as America adapted the ideas of Greek democracy and the Roman Republic's representative democracy model.
Step-by-step explanation:
The civilization that had the most influence on American government is ancient Greece, particularly during the Classical period. Greek contributions to democratic principles and the engagement of citizens in the governance of the state were fundamental in shaping the ideological foundations of the United States. America adapted the ideas of Greek democracy, which emphasized direct citizen participation, and the Roman Republic, which developed the concept of a representative democracy where citizens elect officials to govern on their behalf. These classical roots, coupled with Enlightenment thinking and the legal traditions inherited from England, fused to create a unique American republicanism. The words "democracy" and "republic" come from these ancient Greeks and Romans, underlining the lasting impact of their political philosophies.
While the ancient Greeks were among the first to experiment with democracy, the Romans took these principles and implemented them in the founding of a republic, indicating a shift towards a more structured and expansive form of governance. The Romans also admired Greek culture and integrated it into their society, spreading these ideas across the Mediterranean and into Western Europe. Specifically, Greek intellectual legacy was adapted eagerly by the Romans and, later on, by Americans, whose towns and cities have been named after locations in Greece and Italy, reflecting the admiration of classical civilizations.