"Most of it is unflattering, but it is CIA's history," the CIA's director, Gen. Michael Hayden, said last week in announcing plans to release the documents, which had been considered so sensitive that they were known internally as the agency's "family jewels."

Much of the material had previously entered the public record through nearly 30 years of requests by academics, authors and journalists under the Freedom of Information Act. But publication of the materials Tuesday by the CIA itself marked a major step in the agency's public acknowledgement of its sometimes sordid history.

The documents were compiled beginning in 1973 at the order of then-CIA Director James Schlesinger, who wanted to be prepared for congressional investigations he expected in the wake of disclosures that arose during the Watergate scandal. Schlesinger's successor, William Colby, was outraged at much of the material, which he collected in a report to President Gerald Ford in 1975.

Assassination Plots, Break-Ins and a Possible Kidnapping

Among the disclosures, gleaned from a six-page summary prepared in January 1975 by Associate Deputy Attorney General James Wilderotter and an initial review of documents by NBC News and MSNBC.com, are the following:

The CIA confined a Soviet defector, Yuri Nosenko, in a safe house from April 1964 to September 1967, fearing he might be a plant.

Nosenko, deputy chief of the Seventh Department of the KGB, was responsible for recruiting foreign spies. He claimed to have been the KGB handler of the case of Lee Harvey Oswald, who he said was rejected as not intelligent enough to work as a KGB agent.

Nosenko was eventually released and was given a false identity. He became an adviser to the CIA and the FBI for $35,000 a year and a lump sum $150,000 payment for his ordeal.

The papers indicate that the CIA regularly confined defectors for interrogation, but only outside the United States, and the agency was concerned that the detention of the Soviet defector might violate kidnapping laws. "The possibility exists that the press could cause undesirable publicity if it were to uncover the story," David H. Blee, chief of the Soviet Bloc Division, wrote in a memo.

The CIA conducted surveillance on numerous journalists, including Brit Hume, now an anchor for Fox News. Hume was working for investigative columnist Jack Anderson when he, Anderson and other Anderson associates were put under surveillance in 1972 after Anderson published a column, considered inside the agency as highly damaging, reporting that the CIA was "tilting" toward Pakistan in its Middle East operations.

Another journalist who was placed under surveillance was Michael Getler, then the intelligence reporter for The Washington Post. There was no indication that the CIA conducted any illegal wiretaps or other unlawful operations against Getler.

For 20 years beginning in 1953, the CIA screened and opened mail to and from the Soviet Union that passed through John F. Kennedy International Airport in New York. The operation was approved by three successive postmasters general, the documents indicate.

For three years beginning in 1969, the CIA similarly opened mail to and from China that passed through San Francisco.

From 1963 to 1973, the CIA authorized and funded "behavioral modification" research on Americans without their consent. The research primarily involved observation of their reactions in public, but some of it involved reactions to undisclosed drugs, the documents report. The CIA plotted the assassinations of Cuban President Fidel Castro; Patrice Lumumba, the democratically elected president of the Democratic Republic of the Congo; and Rafael Trujillo, the Dominican dictator.

The papers report that Robert F. Kennedy, attorney general for his brother, President John Kennedy, was involved in planning the operation against Castro, an allegation that his son, Robert Kennedy Jr., denied strongly this week in an interview on MSNBC's "Hardball."

Mob Boss Worries Over Girlfriend

The papers also include some disclosures that can only be described as odd, NBC's Robert Windrem reported.

The Mafia was also involved in the plot to assassinate Castro, the papers reveal, and Sam Giancana, boss of the Chicago mob, once used that connection to seek a personal favor.

According to the documents, Giancana asked Robert Maheu, his contact with the CIA, for help in bugging his girlfriend, Phyllis McGuire, a member of the McGuire Sisters, a popular singing group.

Giancana wanted to know whether McGuire was having an affair with Dan Rowan, half of the Rowan & Martin comedy team. But the CIA technician was caught, and the Justice Department had to get involved at the highest levels - Kennedy, the attorney general - to block prosecution.

The 693 pages of CIA disclosures were turned over in 1975 to three investigative panels - special House and Senate committees and a commission headed by then-Vice President Nelson Rockefeller. Much of the material has since seen the light of day, but Tuesday marked the first time the CIA had publicized and taken formal public responsibility for activities.

In his address last week, to a conference of historians, Hayden acknowledged that the papers "provide a glimpse of a very different time and a very different agency."

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NBC News investigative producer Robert Windrem contributed to this report.

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