The Agora museum is housed in the Stoa of Attalos, a reconstructed building of around 150 B.C. The characteristic feature of the museum is that the exhibits are all closely connected with the Athenian Democracy, as the Agora was the focus of the city's public life
This is an ostracon or ostrakon with Pericles' name written on it. An ostracon (Greek: ὄστρακον) is technically just a piece of pottery (or stone), usually broken off from a vase or other earthenware vessel. But in Ancient Greece, the public would write or scratch a name in the shard of pottery to vote for the banishment or exile of a certain member of society for a period of 10 years, thus giving rise to the term ostracism. It was not a process of justice, offering neither a charge nor a defense. It was often used preemptively as a way to defuse confrontations between rival politicians or neutralizing a potential threat to the state. Pericles, unlike his father Xanthippos, was never actually ostracized.
Pericles or Perikles (c. 495 BC - 429 BC, Greek: Περικλῆς, meaning "surrounded by glory") was a prominent and influential statesman, orator, and general of Athens in the city's Golden Age (specifically, between the Persian and Peloponnesian wars). Some contemporary scholars call Pericles a populist, a demagogue and a hawk, while other scholars admire his charismatic leadership. Thucydides, his contemporary historian, acclaimed him as "the first citizen of Athens".