It was a different time. For example, when ‘the bomb’ was dropped on Hiroshima it was a total surprise to the world. No one talked.
When magazine publishers figured out something was happening in Oak Ridge Tn years ago (because Mountain people weren't subscribing to Scientific American in such high percentages) they were told to keep it to themselves - and they did.
It wasn't like today when anyone will sellout their country for 5 minutes of fame (down from the old fifteen minutes) There were also Germans who came over after the war who worked on the space program... and that was also kept secret.
My father worked on the LEM with one of those German scientists.... we moved from Long Island to live just outside White Sands, New Mexico... to finalize before launch.
We lived in a desert location for 3 or 4 years... watched the landing on an old black and white.
My father was extremely proud of being part of such... and... was not a man to lie... that’s enough for me to believe it was real...