The U.S. National Archives and Records Administration posted to its website roughly 2,200 files containing the documents. The vast majority of the National Archives’ collection of over 6 million pages of records, photographs, motion pictures, sound recordings and artifacts related to the assassination have previously been released.

Larry J. Sabato, director of the University of Virginia Center for Politics and author of “The Kennedy Half-Century,” said it will take time to fully review the records.

“We have a lot of work to do for a long time to come, and people just have to accept that,” he said.

Trump announced the release Monday while visiting the John F. Kennedy Center for the Performing Arts in Washington, saying his administration would be releasing about 80,000 pages.

“We have a tremendous amount of paper. You’ve got a lot of reading,” Trump said.

Before Tuesday, researchers had estimated that 3,000 to 3,500 files were still unreleased, either wholly or partially. And just last month the FBI said it had discovered about 2,400 new records related to the assassination.

Jefferson Morley, vice president of the Mary Ferrell Foundation, a repository for files related to the assassination, said in a statement posted on the social platform X that the release is “an encouraging start.” He said much of the “rampant overclassification of trivial information has been eliminated” from the documents.

The National Archives said on its website that in accordance with the president’s directive, the release would encompass “all records previously withheld for classification.” But Morley said what was released Tuesday did not include two-thirds of the promised files, any of the recently discovered FBI files or 500 Internal Revenue Service records.

“Nonetheless, this is the most positive news on the release of JFK files since the 1990s,” Morley said.

Interest in details related to Kennedy’s assassination has been intense over the decades, with countless conspiracy theories spawned about multiple shooters and involvement by the Soviet Union and mafia.

He was killed Nov. 22, 1963, on a visit to Dallas, when his motorcade was finishing its parade route downtown and shots rang out from the Texas School Book Depository building. Police arrested 24-year-old Lee Harvey Oswald, who had positioned himself from a sniper’s perch on the sixth floor. Two days later nightclub owner Jack Ruby fatally shot Oswald during a jail transfer.

A year after the assassination, the Warren Commission, which President Lyndon B. Johnson established to investigate, concluded that Oswald acted alone and that there was no evidence of a conspiracy. But that didn’t quell a web of alternative theories over the decades.

Oswald was a former Marine who defected to the Soviet Union before returning home to Texas.

Files in the new release included a memo from the CIA’s St. Petersburg station from November 1991 saying that earlier that month, a CIA official befriended a U.S. professor there who told the official about a friend who worked for the KGB. The memo said the KGB official had reviewed “five thick volumes” of files on Oswald and was “confident that Oswald was at no time an agent controlled by the KGB.”

The memo added that as Oswald was described in the files, the KGB official doubted “that anyone could control Oswald, but noted that the KGB watched him closely and constantly while he was in the USSR.” It also noted that the file reflected that Oswald was a poor shot when he tried target firing in the Soviet Union.

In the early 1990s, the federal government mandated that all assassination-related documents be housed in a single collection in the National Archives and Records Administration. The collection was required to be opened by 2017, barring any exemptions designated by the president.

Trump, who took office for his first term in 2017, had said that he would allow the release of all of the remaining records but ended up holding some back because of what he called the potential harm to national security. And while files continued to be released during President Joe Biden’s administration, some remained unseen.

Sabato said that his team has a “long, long list” of sensitive documents it is looking for that previously had large redactions.

“There must be something really, really sensitive for them to redact a paragraph or a page or multiple pages in a document like that,” he said. “Some of it’s about Cuba, some of it’s about what the CIA did or didn’t do relevant to Lee Harvey Oswald.”

Some of the previously released documents have offered details on the way intelligence services operated at the time, including CIA cables and memos discussing visits by Oswald to the Soviet and Cuban embassies during a trip to Mexico City just weeks before the assassination.