The document provides information about National History Day and the Bronx Lab School's History Day contest. It outlines 5 steps for students to participate, including picking a general topic related to one of the 20th century wars or revolutions, choosing a specific topic to research, and presenting their learning through a research paper, exhibit, documentary, or website. It then provides background context on some major historical events and eras leading up to the 20th century. Finally, it gives overviews of the four general topic areas for the contest - World War I, the Russian Revolution, World War II, and the Cold War - listing when each occurred, the main participants, and a brief explanation of why each war or conflict took place.