400s B.C.: A plague of unknown cause and the Peloponnesian war have a profound effect on the shape of Greek literature.

Today: Cancer and AIDS, both of which have been called "the plague of the twentieth century," as well as both World Wars and the Vietnam War have resulted in entire subgenres of literature and have greatly affected the course of postmodern writing.

91-87 B.C.: Rome's Italian allies go to war to remove Rome from her predominance in the Italian peninsula. Rome gains the upper hand in the dispute by granting full citizenship to the residents of all Italian cities once they reaffirm their loyalty to Rome.

Today: The Civil Rights movement of the midtwentieth century, led by such renowned figures as Dr. Martin Luther King Jr. and Malcolm X, brings to pass the end of much discriminatory legislation and the implementation...