Final answer:
Ancient Athens had a direct democracy with citizen participation limited to adult males, whereas the United States is a representative democracy with a broader franchise. Athens citizens were directly involved in legislation and judicial processes, unlike U.S. citizens who elect representatives to perform these functions.
Step-by-step explanation:
The government of ancient Athens was different from that of the United States in several key ways. Most notably, Athens practiced direct democracy, where all male citizens could participate in decision-making directly in the Assembly. In contrast, the United States is a representative democracy, where citizens elect representatives to make decisions on their behalf.
Athens was unique in its time for granting this significant political power to its citizens, though it must be emphasized that citizenship was narrowly defined. Citizen participation was limited to adult male citizens, excluding women, enslaved people, and foreign residents from political processes. Additionally, Athenian citizens could be chosen by lot to sit in the Council and served on juries that interpreted the law.
In contrast, the U.S. government was influenced by Athenian democracy but adapted the concept to form a republic with a constitution, a system of checks and balances, and an extended franchise to all adults regardless of gender or social status (with specific historic exceptions that have been gradually rectified over time).