The National Archives has released thousands of records related to the assassination of former President John F. Kennedy.

The release of 12,879 new files, the largest dump since 2018, comes nearly six decades after Kennedy was shot and killed in Dallas, becoming the fourth U.S. president to have been assassinated while in office. President Biden ordered the documents’ release earlier in the day ahead of a Thursday deadline.

Lawmakers in 1992 passed legislation requiring all remaining government records about the assassination to be released by Oct. 2017, unless they posed certain risks to national defense or intelligence, but former President Trump and Biden both issued extensions.

That set off a legal challenge filed by the Mary Ferrell Foundation, a nonprofit that curates an online collection of the assassination records, arguing the extensions were unlawful based on the 1992 legislation.

Biden issued the most recent extension, which lasted one year, arguing that the coronavirus pandemic impeded agencies’ ability to review the records by the earlier deadline.

The president’s order on Thursday stated that almost 16,000 records remained redacted, and Biden approved the release of more than 70 percent of them.

But an unspecified “limited” number of records that remain the subject of review were not included in the batch, and Biden’s order gives federal agencies and the National Archives until May 1, 2023, to make recommendations about whether they must still be kept private.

Biden ordered the remaining records to be publicly released by June 30, 2023, unless they meet narrow exceptions.

“Agencies shall not propose to continue redacting information unless the redaction is necessary to protect against an identifiable harm to the military defense, intelligence operations, law enforcement, or the conduct of foreign relations that is of such gravity that it outweighs the public interest in disclosure,” Biden’s order states.

The Hill has reached out to the Mary Ferrell Foundation for comment.

The National Archives had released various batches of documents in recent years, with the most recent dump of 1,491 files being published exactly one year ago. 

Prior to Thursday, the Archives had released roughly 55,000 total documents since the deadline originally imposed by Congress.