This short won the Academy Award for Documentary Short. There will be mild spoilers ahead: This is a short composed entirely of archival footage.
Robert Fresco's and Denis Sanders's "Czechoslovakia 1968" looks mainly at Czechoslovakia's history from its founding through the Warsaw Pact invasion that eviscerated the political liberalization. Consisting entirely of footage with no dialogue, it shows the country's days as a predominantly agricultural society, and then the Nazi occupation, and then Soviet takeover.