Millions of documents related to the 1963 assassination of President John F. Kennedy in Dallas have already been made public, but President Donald Trump has ordered the release of thousands of still-classified files.

Trump signed the executive order Thursday, January 23 as part of a flurry of executive actions taken in the first week of his second term.

Many people who have studied what’s been released so far say the public shouldn’t anticipate any earth-shattering revelations, but there is still intense interest in details related to the assassination and the events surrounding it. And the possibility of significant new information is tantalizing to researchers.

Here are some things to know:

Trump's order
Thursday's order directed the national intelligence director and attorney general to develop a plan within 15 days to release the records related to Kennedy’s assassination. It’s not clear though when the records might actually be made public.

The order also aims to declassify the remaining federal records related to the 1968 assassinations of Sen. Robert F. Kennedy and the Rev. Martin Luther King Jr. It says a plan must be developed within 45 days for the release of those files.

After signing the order, Trump handed the pen to an aide and directed that it be given to Robert F. Kennedy Jr., whom Trump has nominated to be the health secretary. He's the nephew of John F. Kennedy and son of Robert F. Kennedy. The younger Kennedy, whose anti-vaccine activism has alienated him from much of his family, has said he isn’t convinced that a lone gunman was solely responsible for his uncle's the assassination.

November 22, 1963
When Air Force One carrying JFK and first lady Jacqueline Kennedy touched down in Dallas, they were greeted by a clear sky and enthusiastic crowds. With a re-election campaign on the horizon the next year, they went to Texas for a political fence-mending trip.

But as the motorcade was finishing its parade route downtown, 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.

The JFK files
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 of over 5 million records 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 remain unseen.

Larry J. Sabato, director of the University of Virginia Center for Politics and author of “The Kennedy Half-Century," said that most researchers agree that roughly 3,000 records have not yet been released, either in whole or in part, and many of those originated with the CIA.

There are still some documents in the JFK collection that researchers don’t believe the president will be able to release. Around 500 documents, including tax returns, weren’t subject to the 2017 disclosure requirement.

What's been learned
Some of the documents already released 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. The former Marine had previously defected to the Soviet Union before returning home to Texas.

One CIA memo describes how Oswald phoned the Soviet embassy while in Mexico City to ask for a visa to visit the Soviet Union. He also visited the Cuban embassy, apparently interested in a travel visa that would permit him to visit Cuba and wait there for a Soviet visa. On October 3, more than a month before the assassination, he drove back into the United States through a crossing point at the Texas border.

Another memo, dated the day after Kennedy’s assassination, says that according to an intercepted phone call in Mexico City, Oswald communicated with a KGB officer while at the Soviet embassy that September.

The releases have also contributed to the understanding of that time period during the Cold War, researchers said.