525-456 B.C.: In 510 B.C., a political reformer named Clisthenes overthrows the tyrant Hippias and establishes in Athens a republic ruled by popular democracy.

Today: Democracy in its various forms remains one of the most important philosophies of world government. While democracy today takes various forms—direct, representative, presidential, parliamentary—all these concepts have their genesis with the Attic republic.

525-456 B.C.: As the capital of the Dalian League, Athens evolves into a commercial and cultural center, with visitors and residents from throughout the known world. Teachers, artists, philosophers, and religious leaders gather at public forums to discuss their ideas and opinions.

Today: American society mirrors Athens in its emphasis on freedom of speech and religion, and its belief in the strength of diversity and multiculturalism.

525-456 B.C.: Theatre in Athens is largely comprised of a religious festival celebrating the god...