In June 1973, a C.I.A. employee wrote a memo at the request of William E. Colby, the agency’s director, listing various ways the C.I.A. had, to put it delicately, “exceeded” its charter over the years.

The seven pages matter-of-factly described break-ins at the French Consulate in Washington, planned paramilitary attacks on Chinese nuclear facilities and injections of a “contaminating agent” in Cuban sugar bound for the Soviet Union. The memo ended with an offhand aside about John A. McCone, the agency’s former director.

“Finally, and this will reflect my Middle Western Protestant upbringing, McCone’s dealings with the Vatican, including Pope John XXIII and Pope Paul VI, would and could raise eyebrows in certain quarters,” the author wrote.

It was just one paragraph in the roughly 77,000 pages the National Archives posted online this week as part of the latest — and supposedly final — release of its vast collection of documents related to the assassination of President John F. Kennedy.

But for some of the scholars who immediately started combing through the documents, the brief passage, seen unredacted for the first time, raised eyebrows for sure.

“This opens a door on a whole history of collaboration between the Vatican and the C.I.A., which, boy, would be explosive if we could get documents about it,” said Peter Kornbluh, a senior analyst at the National Security Archive, an independent research center at George Washington University.

“Which of course,” he added, “we will now try to do.”

The document drop may have been a disappointment for those hoping for juicy revelations about the Kennedy assassination. But for scholars steeped in the history of intelligence agencies and the secret side of American foreign policy, there have been revelations aplenty.

They include information about C.I.A. involvement in various attempted coups, election interference in countries around the world and connections that ran to the top of some foreign governments. To see the documents all drop suddenly, without redactions, was remarkable to scholars.

“I didn’t think I’d live to see it,” Mr. Kornbluh said.

That the release included so much material with no obvious connection to the assassination reflected the broad intentions of the President John F. Kennedy Assassination Records Collection Act, a 1992 law passed after the Oliver Stone film “JFK” prompted a resurgence of conspiracy theorizing.

The law ordered that all government records related to the assassination and various investigations be gathered in one place and released within 25 years, with some exceptions for grand jury secrecy, tax privacy and concern for “identifiable harm” to national security.

And the law defined “assassination-related record” broadly, taking in a swath of documents related to the inner workings and covert operations of the C.I.A. and F.B.I., including many gathered by the Senate’s Church Committee, established in 1975 to investigate abuses by the intelligence agencies.

Before this week, 99 percent of the roughly six million pages in the collection had already been made public. Only several thousand documents remained redacted, and as few as 50 withheld in full, according to past statements from the archives.

Tulsi Gabbard, the director of national intelligence, said this week that only a few documents, which remained under a court seal because of grand jury rules, were still secret. The federal government is working to get those documents unsealed.

The release of the newly unredacted material had long been opposed by the C.I.A. because it would give up the names of its sources. But equally important to the agency was the desire to protect its mid-20th-century tradecraft: how well it had penetrated the Egyptian government’s communications, or the depth of its contacts in France.

Unredacted passages in the new documents revealed how the C.I.A. wiretapped phones in Mexico City in 1962. While that may be interesting in a Cold War spy movie kind of way, it has no bearing on whether American spy agencies can listen to a phone call made on an encrypted app on a modern cellphone.

But for historians, the agency’s closely guarded “sources and methods” are important to filling out the full historical picture. And some of the new material is startling, they said.

Fredrik Logevall, a Harvard historian who is working on a multivolume biography of Kennedy, said that it was remarkable to see a full version of an unredacted 1961 memo by Arthur Schlesinger Jr., an aide to Kennedy, written shortly after the Bay of Pigs fiasco, warning of the growing power of the C.I.A. and calling for it to be reorganized.

Newly visible passages revealed, among other things, that nearly half of the political officers in American embassies around the world were working for the C.I.A. “That’s astonishing,” Dr. Logevall said.

He also cited a now-unredacted 41-page memo of minutes from meetings between 1962 and 1963 of the President’s Foreign Intelligence Advisory Board, which included many suggestive new details, including some related to surveillance of China’s efforts to develop a nuclear bomb.

There was also an unredacted 1967 report by the C.I.A.’s inspector general on the 1961 assassination of the Dominican dictator Rafael Trujillo that now shows the names of all the C.I.A. agents involved in the plot.

“Without the 1992 law, all of this probably would have been under lock and key forever,” Dr. Logevall said.

The revelation of sources’ identities causes the C.I.A. deep angst, on principle and because it undermines efforts to recruit sources today.

“These relationships are secret for a reason,” said Nicholas Dujmovic, a retired C.I.A. historian. “If people don’t want others to know that they were cooperating with the C.I.A., for whatever reason, we have a moral obligation to keep these relationships secret, because that was the going in agreement.”

Arturo Jimenez-Bacardi, a historian at the University of South Florida and researcher for the National Security Archive, said the documents also revealed efforts to interfere in elections in Finland, Peru and Somalia that had been rumored but undocumented, or entirely unknown. There was also new information, he said, about C.I.A. involvement in failed and successful coups in various countries, including Brazil, Haiti and what is now Guyana.

A 1964 C.I.A. inspector general report on the workings of the agency’s station in Mexico City was particularly significant, he said, because it contained one of the most detailed accounts available of how the agency organized its ground operations.

A heavily redacted version was released in 2022. But newly visible passages revealed that Adolfo López Mateos, the president of Mexico, had approved a joint surveillance operation against Soviets in Mexico.

The memo also described a “highly successful project” aimed at “rural and peasant targets,” led by a Catholic priest who had created an extensive network of youth groups, credit unions, agricultural co-ops and study centers — presumably, Dr. Jimenez-Bacardi said, to make sure people “don’t go on the Soviet path.”

The White House said on Thursday that all remaining classified documents in the collection are now open for research at the National Archives, with additional pages still set to be digitized and posted online “in the coming days.”

Dr. Jimenez-Bacardi said he was eager to see the Church Committee interviews and depositions of former directors of the C.I.A., but had not yet found them.

Parts were included in previous releases. “But there are still secrets in those depositions,” he said.