From the Atlas Obscura:
The residents of Los Alamos, New Mexico—a town that wasn’t supposed to exist—lived in a viscous state of secrecy during World War II. To disguise the existence of the nuclear bomb being built there, the group of Manhattan Project scientists, security personnel, and families needed to consider and reconsider their every move. They couldn’t leave “the Hill,” as Los Alamos was known, without required passes. Their mail reached New Mexico through a series of forwarding addresses set up across the United States, arriving in a P.O. box 20 miles away in Santa Fe. Food was purchased from a single commissary; a trip to Santa Fe was “a major event.”
When they first arrived at Los Alamos, they were told to buy train tickets to New Mexico from a variety of locations. One Princeton physicist recounted how he and his colleagues had to avoid the local train station, because it was so small, and too many people purchasing tickets to Albuquerque from there might raise suspicions.
The importance of silence at Los Alamos was doubly true for scientific breakthroughs. One woman, Adrienne Lowry, only learned that her husband Joseph Kennedy had discovered plutonium when she was cataloguing books and kept seeing the acronym “PU.” When she asked her husband about it, he confessed that “PU” stood for plutonium—an element he’d helped to identify a few years earlier.
. . . .
One of the most significant features of this elaborate security apparatus was the scientific library, a virtually unknown space that, during the 1940s, housed the secrets of the nuclear bomb.
. . . .
Nestled alongside the massive Los Alamos lab—which Lisa Bier in Atomic Wives and the Secret Library at Los Alamos described as emanating an “aura of utilitarian haste” with its unpaved streets and barbed wire gates manned by guards—the library appeared quite bleak. The photos that exist today show a small space crammed with books, shelves, file cabinets, and a Ditto machine (an early copier). Because the library was expected to be demolished after the war, everything was built from cheap wood.
The library had two sections: the main area, pictured at the top, and the document room—a locked vault containing reports and designs from Los Alamos and the other Manhattan Project sites. The library’s all-female staff—a mix of wives and Women’s Auxiliary Army Corps officers—needed to catalog, secure, and distribute thousands of books and manuscripts in a matter of months.
The rapid pace made the work so intense that, when one WAAC officer was offered a job at the library, she “took a look at the huge stack of technical reports from chemical companies, piled up ‘like a teepee,’ the classification of which would be her primary task.” According to Atomic Wives and the Secret Library at Los Alamos, “she avoided this sentence, which she termed ‘solitary confinement,’ by opting instead to drive trucks.”
. . . .
Here is a puzzle. You have no library experience, and you are tasked with a) heading a top secret facility, b) devising security protocols to ensure the U.S. military’s greatest secrets stay hidden, and c) importing thousands of documents to a site in the middle of nowhere—all in a vanishingly small window of time as World War II unfolds. How do you do it?
Link to the rest at Atlas Obscura
Here’s a book I enjoyed (The Wives of Los Alamos):
https://www.amazon.com/gp/product/B00GC53AHM/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
I am skeptical of the much-vaunted secrecy. My grandfather worked at Oak Ridge during the war. He had nothing to do with the Manhattan Project. He was a chemical engineer working on gunpowder. The families were instructed that if anyone asked what Dad was working on they were to answer “bubble gum” and report the inquiry. So one day my Mom, who was a pre-teen at that time, comes home and tells Grandma about this science fiction story she had read about an atomic blaster. (The most amazing part of this story to me is that my mother read science fiction as a girl. I would never have guessed.) Grandma was a smart cookie and knew the proper response: She told my mother in no uncertain terms to shut the fuck up and never ever talk about atomic blasters to anyone, and certainly not to anyone in authority.
The moral of this story is that the implications of nuclear physics were well understood among the scientifically literate. It only seemed a great secret because so few people were scientifically literate. Nuclear physics seemed the most abstruse of fields before the war.