The March 1952 document "A Brief History of Communications Intelligence in the United States" by Captain Laurance F. Stafford, USN (Retired) has been declassified by the National Security Agency and released to the public. It was originally classified TOP SECRET SUEDE. The document is a 24-page PDF. The document tells the history of COMINT prior to Pearl Harbor, beginning with the entry of the U.S. into WWI, when Herbert O. Yardley set up MI-8, the "American Black Chamber" to do cryptology work. On a quick scan I didn't see anything that wouldn't already be familiar in broad strokes to readers of James Bamford's The Puzzle Palace or Body of Secrets, though there may be some details not previously public, such as the number of staff working on cryptography.