What ancient government structure are in american government

The US government is a Democratic Republic, which come from the Greek democracy and the Roman Republic.
I don't know if it's the answer but I hope it helps

In my honest opinion , i’d say franklin d roosevelt was a president that impacted our nation , i say this because fdr is voted among top three best us presidents and he was the longest serving president by 3 terms , usually presidents only supposed to have two terms increments of 4 years , equivalent to 8 years total before election time. and he established the fdic , through the 1933 banking act and he established the us , social security system , during his presidency, and established a national minimum wage , through the fair labor standards act , fdr led the allied coalition to victory in wwii and he played a major role in the creation of the united nations.