The Blackhawks came from the Nazi-occupied nations of Europe; Poland, Norway, Holland, and France. These men grew tired of sitting by the sidelines and rose up to free Europe from Nazi oppression. When the Justice League traveled back in time to thwart Vandal Savage's interference with the historical events of World War II, they teamed up with the Blackhawks to destroy the Nazi's artificially advanced factories and their American invasion force after it was forced to turn back to Europe.