Arlington Hall was the headquarters of the United States Army's Signal Intelligence Service (SIS) cryptography effort during the years around World War II.
History[]
Roger Dooley requested a cryptographer from Arlington Hall in order to decrypt an encoded message that was received through Sasha Demidov's Remote Typewriter. The cryptographer was unable to decipher the message, and wanted to return to Arlington Hall with the message, but Peggy Carter managed to easily decipher it upon realizing that the original message had been written in Russian.[1]