SOLO
Operation SOLO was a long-running FBI program to infiltrate the Communist Party of the United States and gather intelligence about its relationship to the Union of Soviet Socialist Republics, China, and other communist nations. It officially began in 1958 and ended in 1977, although Morris and Jack Childs, two of the principal agents in the operation, had been involved with the Bureau for several years prior. The files range from March 1958 to April 1966. Read a related story at http://www.fbi.gov/news/stories/2011/august/byte-out-of-history-communist-agent-tells-all/.