While I agree in spirit on the concern about political interference in science, the Manhattan Project was actually one of the most secretive, tightly controlled government programs in US history.
In addition many scientists involved (like Oppenheimer) later faced political persecution during the McCarthy era.
American atomic research succeeded despite, or perhaps because of, intense state control and funding
The "raw material" of the Manhattan Project was a flourishing community of researchers, including many European exiles; "secretive, tightly controlled" management is simply the only reasonable way to run such a military program.
Consider that at the same time the Third Reich also had a nuclear weapons research program, and it went nowhere.
Well, many of the researchers would have been killed if they stayed in Germany. It kinda helps being alive when researching how to build a nuclear bomb.
The Manhattan project was an engineering project, not so much a scientific one. It was only made possible because the science and theories behind it were discovered first.
Yeah it probably isn't the best project to highlight the sentiment, but it was well known one and immediately came to mind in a period that had the contrasting factor.
I don't particularly think that the secrecy or control of a single group really reflects on the overall culture however. We wouldn't call phreakers authoritarian just because they weren't publishing their exploits in the newspaper or letting any new person fully into their circle.
Also the prosecution and harassment of communists/leftists and minorities in the US during that era is why I stipulated less oppressive rather than unoppressive.
In addition many scientists involved (like Oppenheimer) later faced political persecution during the McCarthy era.
American atomic research succeeded despite, or perhaps because of, intense state control and funding