This letter was received by Sgt. K. Patterson, a member of the Women’s Army Corps in Los Alamos. At one time, she feared she might lose her job because her brother, who was stationed overseas, sent letters to her claiming that he knew inside secrets about Los Alamos. When her commanding officer found out about the incident, she didn’t write to her brother for the duration of the war, and she received no further mail from him. Later she learned her brother was friends with a soldier who had lived in the Los Alamos area prior to the war! Courtesy/Debra Krikorian

Mail censorship proved to be one of the more controversial aspects of wartime life in Los Alamos. Both incoming and outgoing mail at the top-secret military post was checked by army censors starting in December 1943. They ensured that no information about the atomic bomb project, including its location or the famous people associated with it, went beyond the security fences.

Many people who lived in Los Alamos at that time have shared stories about censorship, which, like countless other characteristics of wartime life on “the Hill,” was unique.

“I felt we were at war. Censorship was a natural thing, and it didn’t particularly bother me,” recalled physicist Darragh Nagle in an oral history interview.
Gen. Leslie Groves, the military leader of the Manhattan Project, maintained in his memoir that the scientists on the project requested the censorship.

“One aspect of our security policy at Los Alamos that particularly annoyed everyone was the censorship of mail,” he wrote in Now It Can Be Told. “Originally there was none. Nevertheless, shortly after the first staff members arrived at Los Alamos, rumors began to circulate that some letters had been opened. As the rumors continued to spread, Oppenheimer became most concerned and, since he had no assurance that the mail was not being opened, asked me whether I had ordered any censorship. I had not, and careful investigation of every instance where someone claimed that his mail had been opened convinced me that these claims were without foundation. However, by that time, a number of the more thoughtful members of the laboratory had themselves begun to urge that we institute an official censorship for outgoing mail.”

In spite of General Groves’ assurances that incoming mail censorship claims were unfounded, many stories persist of mail from outside being opened by the censors and having the stamp to prove it.

Physicist Bob Carter recalled receiving a letter from his mother with large sections cut out.

“We ran at full speed from our office to Oppenheimer’s office,” he said. “We showed him the letter, and he grabbed his hat and said, ‘Come on.’ The three of us—Oppenheimer in the lead—went to a different building to find the military officer who was in charge of security. Oppenheimer showed him the letter and said, ‘Don’t you dare do this to anybody’s letter ever again.’”

Unfortunately, the cut out pieces of the letter were thrown away, so Carter never did get the message from his mother.

One young soldier, Paul Numerof, wrote in his memoir, “From time to time, for military personnel, reminders of security regulations were given. Los Alamos, as far as I was aware, was the only army installation where incoming mail, as well as outgoing mail, was censored. The censorship of outgoing mail was easy to understand. But incoming mail? No explanation was ever given. It was just ‘security.’ Every letter I received had a small legend at one end of the envelope: ‘Opened by U.S. Censor.’”

Not all censorship experiences were negative, though. Resident Jean Wilson wrote in Standing By and Making Do: The Women of Wartime Los Alamos, “Our mail was censored. Furthermore, our correspondents were not supposed to know it was censored. The method was simple. Mail went into the box unsealed, the censor read it, sealed it, and sent it on its way. Or, if he didn’t approve of the letter, he sent it back. Sometimes this system proved useful. If one of us intended to send a letter with an enclosure, such as a check, and then forgot to enclose it, the letter would come back with a note from the sensor politely chiding the sender for his absent-mindedness.”

One of the more famous and amusing censorship stories involved Manhattan Project prankster Richard Feynman, who would win a Nobel Prize in 1965. Feynman’s wife, Arline, suffered from tuberculosis and was living at a sanitorium in Albuquerque. Because they enjoyed puzzles and other challenging games, the couple would write to each other in code. The army censors strongly objected! Finally, the Feynmans agreed to put a key to the code in each letter, if the censors promised to destroy the key before sending the letter along to its intended recipient. This arrangement worked to everyone’s satisfaction.