Answer:
the Roman Empire.
Explanation:
The government of the United States had a similar political branch as the Roman empire. The Roman empire had a lasting legacy in political aspects such as government, law, language, etc. Though the United States political ideas came from the United Kingdom they could be traced directly to the Roman empire.
Just like the Roman Republic, the United States has three branches and named Senate after the name of Senate of Rome.
Therefore, the Roman empire is the correct answer.
