Answer · confidence: partial
How was CHAOS's 300,000-civilian computer index built, and do search logs survive?
Research question: What do the surviving records say about how the CHAOS computer index of 300,000 civilians was built, searched, and what fields it held, and do any retrieval logs or index printouts survive?
The records show that names of persons in intelligence source reports and in case officers' contact, briefing, and debriefing reports were computer-indexed 36. A computer printout on a person, organization, or subject listed every document, file, or communication where the name appeared 3. The detailed 201 files on about 7,200 citizens recorded fields such as place of birth, family members, and organizational affiliations, and some were supplemented with mail-intercept material 78. The CHAOS records, including the indexes, were destroyed in 1990, and apart from a few records in the agency's database and records tied to specific foreign intelligence or counter-intelligence matters, none survived 910. The CIA later enclosed listings of available documents on related programs, though their page counts were not always accurate 11. The facts do not mention any retrieval logs, and the newest fact is from November 2010, about 16 years before October 2026.
Checked 2026-10-21. Only documented and supported facts are used.
Dig deeper on this questionSources
[1] supported
Police departments across the country cooperated with the CIA's CHAOS program, which amassed a computer index of 300,000 names of American people and organizations, plus extensive files on 7,200 citizens.
"Police departments across the country cooperated in tandem with the agency, amassing a "computer index of 300,000 names of American people and organizations, and extensive files on 7,200 citizens.""Central Intelligence Agency
[2] supported
Project MERRIMACK's twin program, Project RESISTANCE, and MERRIMACK itself were branch operations that passed civilian information up to the parent program, Operation CHAOS.
"In addition, the twin projects were branch operations that relayed civilian information to their parent program, Operation CHAOS ."Project MERRIMAC
[3] documented
The names of all persons mentioned in intelligence source reports received by Operation CHAOS were computer-indexed, and a computer printout on a person, organization, or subject listed every document, file, or communication where the name appeared.
"The names of all persons mentioned in intelligence source reports received by Operation CHAOS were computer-indexed. The computer printout on a person or organization or subject would contain references to all documents, files or communications traffic where the name appeared."Chapter 11 Special Operations Group- “‘Operation CHAOS” Responding
[4] supported
The CIA launched a domestic surveillance program code-named Chaos in the fall of 1967, and it lasted a total of seven years.
"Thus, in the fall of 1967, the CIA launched a domestic surveillance program code-named Chaos that would linger for a total of seven years."Central Intelligence Agency
[5] supported
Operation CHAOS agents built a computerized index of more than 300,000 names of American citizens and organizations connected to dissident movements.
"In both their domestic training and their international work, agents collected the names of American citizens and organizations connected to dissident movements, creating a computerized index of more than 300,000 names."Nixon and Johnson Pushed the CIA to Spy on U.S. Citizens, Declassified Documents Show
[6] supported
Case officers' contact, briefing, and debriefing reports were carefully reviewed, and all names, organizations and significant events in them were then indexed in the Operation's computer.
"all names, organizations and significant events were then indexed in the Operation’s computer."Chapter 11 Special Operations Group- “‘Operation CHAOS” Responding
[7] supported
About 7,200 American citizens had more detailed "201" files opened on them, which recorded fields such as place of birth, family members, and organizational affiliations.
"Of those, approximately 7,200 American citizens had more thorough “201” files opened on them, deeper portraits which included information such as their place of birth, their family members and their organizational affiliations."Nixon and Johnson Pushed the CIA to Spy on U.S. Citizens, Declassified Documents Show
[8] supported
Some of the 201 files were supplemented with material from a CIA mail-intercept program that covertly read postal correspondence between the United States and the USSR.
"The CIA also supplemented some of these “201” files with information gathered through a CIA mail-intercept program, wherein the CIA covertly read postal correspondence between the United States and the USSR."Nixon and Johnson Pushed the CIA to Spy on U.S. Citizens, Declassified Documents Show
[9] supported
The CIA's CHAOS records, including the indexes, were destroyed in 1990.
"The records of this operation, including the indexes, were destroyed in 1990 pursuant to a recommendation of the Commission on CIA Activities within the United States"CIA Documents on Project MERRIMACK
[10] documented
Apart from a few records in the agency's database of previously released records and records tied to specific foreign intelligence or counter-intelligence matters, no CHAOS records or indexes survived.
"With the exception of a few records contained in our database of “previously released records” and any records which might relate to specific foreign intelligence or counter-intelligence matters, no CHAOS records or indexes survived."CIA Documents on Project MERRIMACK
[11] supported
The CIA enclosed listings of available documents on Project Resistance, CHAOS, MHCHAOS, and MERRIMACK, and the page counts on the enclosed printouts were not always accurate.
"Because the page counts on the enclosed printouts are not always accurate, please do not send payment in advance."CIA Documents on Project MERRIMACK