There's multiple reasons why direct democracy was working in Athens and not in the United States. One of those reasons is the size of the population. Athens was a city-state, thus it was very small with very small population, so direct democracy was possible in practice. The United States are enormous, and the population is very big, which makes it very impractical for direct democracy to be practiced. Another reason is that Athens was not ruled by political parties, but a council, so it was much more united, while the United States have a big division, easily seen by region, where there's two contrasting political parties and supporters, which would make a chaos if direct democracy is implemented.
Democracy in ancient Greece served as one of the first forms of self-rule government in the ancient world. The system and ideas employed by the ancient Greeks had profound influences on how democracy developed, and its impact on the formation of the U.S. governmen
