Short answers, pulled from the story.
The Classical period began in 510 BC when Spartan troops helped Athenians overthrow King Hippias. It conventionally ended at the death of Alexander the Great on the 23rd day of May 323 BC.
Cleisthenes reformed Athens with support from the middle class and pro-democracy citizens to create isonomic institutions. He organized about 130 demes as basic civic elements and established ostracism for equal rights among male citizens.
The Battle of Marathon was won by a Greek army consisting of 9,000 Athenian hoplites and 1,000 Plataeans led by Miltiades. This defeat occurred in Attica when Darius sent a Persian fleet to punish the Greeks.
War broke out in 431 BC between the Delian League led by Athens and the Peloponnesian League led by Sparta. The conflict included an outbreak of plague that killed Pericles and concluded with the Peace of Nicias in 421 BC before hostilities resumed.
Philip II became regent for his nephew Amyntas in 359 BC and was acclaimed king shortly thereafter. He expanded Macedonia into Paeonian, Thracian, and Illyrian territory while conquering Amphipolis in 357 BC and Pydna in 356 BC.