How did cultures of both ancient greece and rome influence the political system of the united states?

Ancient Greece left the West a rich legacy. Part of that heritage is democracy, a representative system of government that differed from tyranny, the common system of political organization of ancient Greek states. It was born in Athens. From Rome, we got the institution of the Senate, a deliberative body that held much power in ancient Rome. The classical Greco-Roman culture is the bedrock of Western culture.  

Explanation:

in mcculloch v. maryland (1819) the supreme court ruled that congress had implied powers under the necessary and proper clause of article i, section 8 of the constitution to create the second bank of the united states and that the state of maryland lacked the power to tax the bank.

gibbons v. ogden, (1824), was a landmark decision in which the supreme court of the united states held that the power to regulate interstate commerce, granted to congress by the commerce clause of the united states constitution, encompassed the power to regulate navigation.