The Puzzle Palace is a book written by James Bamford and published in 1982. It is the first major, popular work devoted entirely to the history and workings of the National Security Agency (NSA), a United States intelligence organization. The title refers to a nickname for the NSA, which is headquartered in Fort Meade, Maryland. In addition to describing the role of the NSA and explaining how it was organized, the book exposed details of a massive eavesdropping operation called Operation Shamrock. According to security expert Bruce Schneier, the book was popular within the NSA itself, as "the agency's secrecy prevents its employees from knowing much about their own history". Research and publication The NSA describes Bamford's research process in a partially declassified history of postwar American cryptography. The history begins by describing how Bamford approached Houghton-Mifflin with a proposal to write a book on the NSA. The publisher accepted and paid Bamford a $7,500 advance. According to the NSA's historical account, "Public Law 86-36 had served as a useful barrier against this type of research, but Bamford proved to be cleverer than others. He began with a barrage of requests for information under the Freedom of Information Act (FOIA)." Bamford eventually discovered "the Mother Lode," a collection of documents deposited at the George C. Marshall Foundation Library by former NSA chief cryptologist William Friedman. These documents included copies of the NSA Newsletter, addressed to "NSA Employees and their families." The account continues, "Bamford then submitted a FOIA request for the entire collection, using as his rationale the offending phrase indicating that the information had been intended for dissemination to uncleared people." The FOIA requests gave Bamford access to an only lightly redacted set of documents, and a former NSA employee later gave Bamford access to an almost complete collection. During the 1975 Church Committee hearings, the United States Department of Justice (DOJ) had investigated the legal culpability of various intelligence agencies. Bamford submitted a FOIA request for resulting documents, and received most of their report on the NSA. The DOJ did not inform the NSA of the release because the investigation was ongoing, and the NSA was a possible target. The released papers were later to become the subject of threatened litigation, and their release prompted eventual rule changes that allowed for document reclassification. According to the NSA's history, "the document, with some Justice redactions, contained a good deal