Julius and Ethel Rosenberg were American citizens spying on behalf of the Soviet Union. The couple was accused of providing top-secret information about radar, sonar, jet propulsion engines, and valuable nuclear weapon designs; at that time the U.S. was the only country in the world with nuclear weapons.
Convicted of espionage in 1951, they were executed by the federal government of the U.S. in 1953, in Ossining, New York, becoming the first American civilians to be executed for such charges and the first to suffer that penalty during peacetime.1https://www.nytimes.com/2015/08/13/opinion/what-the-kgb-files-show-about-ethel-rosenberg.html2https://www.washingtonexaminer.com/weekly-standard/the-new-york-times-gets-greenglass-wrong3https://www.britannica.com/biography/Julius-Rosenberg-and-Ethel-Rosenberg
Julius Rosenberg joined the Army Signal Corps Engineering Laboratories at Forth Monmouth, New Jersey from 1940 to 1945 as an engineer-inspector. He was fired when the U.S. Army discovered his previous membership in the Communist Party.4https://books.google.com/books?id=Ok_A5UV1mdoC&pg=PA262#v=onepage&q&f=false