What you need to know a second set of documents concerning President John F. Kennedy's assassination. Kennedy was released by the Trump administration late Tuesday night, after another tranche was put online earlier in the evening, giving professional historians, curious amateurs and zealous conspiracy theorists another shot at uncovering revelations about the killing that still fascinates America more than six decades later.

Between them, the two batches of documents made public on Thursday came to about 63,400 pages, according to the National Archives, though it was unclear how many of those files were actually new, or had previously been released in part or in whole. Officials have said 99 percent of the government’s records relating — sometimes very tangentially — to the Kennedy assassination were already public.

In January, President Trump issued an executive order directing the release of the documents. On Monday, he abruptly announced that they would be released on Tuesday, initiating a 24-hour scramble by intelligence agencies. The first batch of papers, typewritten reports and blurry photocopies offered no major revelations, at least at first glance. But scholars held out hope that the documents might offer new details or at least shed light on persistent questions about an event that traumatized a nation and remains the subject of conspiracy theories six decades later.

Mr. Trump, in teasing the release on Monday, had said it might include as many as 80,000 pages. He also said there would be no redactions, but an early review found that some information appeared to have been blacked out. It was not clear if more documents would be released on Wednesday.

Historians have stated that they did not anticipate any information that would contradict the fundamental facts of the case, namely that Lee Harvey Oswald shot and killed Kennedy while he was traveling through Dallas in an open-car motorcade on November 22. 22, 1963.

What you need to know: Difficult reading: The documents released Tuesday were, in many cases, blurred and difficult to read, no doubt reflecting their age — many of them were typed or written a half-century ago — and because they are photocopies. They were not categorized or presented in any organized way, leading some historians to say it might take days to assess them all.

Early takeaways: Tim Naftali, a Columbia University professor and former director of the Nixon Presidential Library and Museum, said what he saw convinced him that the information had been kept secret all these decades not because it included inflammatory information about the assassination, but rather to mask highly sensitive details about C.I.A. intelligence-gathering.

Second time around: This is the second release of Kennedy papers under Mr. During his first term, Trump wanted to eliminate them all. He ultimately agreed to some redactions to protect intelligence-gathering information. This is likely to be one of the last releases of Kennedy papers, considering that only about 1 percent of what is in the government’s possession — about six million pages in all, plus physical exhibits — remains undisclosed.

Three killings: The latest records were released through an executive order signed by Mr. Trump in January. That order also directed the nation’s security agencies to disclose any remaining documents related to the assassinations of Senator Robert F. Kennedy and the Rev. Dr. Martin Luther King Jr. in 1968. New information on those killings was not readily apparent on Tuesday night.