First radio broadcast of the D-Day landings.
@Tacitus_Kilgore Imagine the impact this had on people who heard it when it was originally aired. While it was known that US and Canadian forces were massing in England, the actual kickoff of the invasion was totally new information.
@Tacitus_Kilgore That's the reason why the weather was so crucial. If they were unable to invade on June 6 or 7, the next opportunity would not have been until June 19 or 20, and Eisenhower thought that it was unlikely they could keep it under wraps that long.