The release of the documents followed an executive order by President Donald Trump in January of this year that required unredacted classified documents in the case to be unsealed.
Historians do not expect many extraordinary discoveries in those documents, which they began to examine in detail after their publication the night before last.
Trump estimated that about 80,000 pages of documents will be unsealed.
US authorities have previously allowed hundreds of thousands of Kennedy documents to be released, but some have been withheld, citing national security concerns.
Many Americans still believe that the man who shot Lee Harvey Oswald did not act alone.
Kennedy was assassinated during a visit to Dallas, Texas on November 22, 1963.
According to the BBC, it is not clear how much of the classified material about Kennedy released by the US National Archives and Records Administration is new.
The vast majority of the National Archives’ collection of more than six million pages of records, photographs, films, audio recordings and artifacts related to the assassination was previously released in partially redacted form, according to experts.
“You have a lot to read. I don’t believe we’re going to redact anything,” Trump told reporters Monday in announcing the release of the classified documents.
However, some of the hundreds of documents unsealed last night appear to have blacked out passages, US media reports, while others are hard to read because they are faded or poorly scanned photocopies.
A government commission determined that President Kennedy was assassinated by Lee Harvey Oswald, a former Marine and self-proclaimed Marxist who defected to the Soviet Union and later returned to the United States.
However, polls have shown for decades that most Americans do not believe that Owald was the only killer.
Unanswered questions have long dogged the case and fueled theories about the involvement of government agents, the mob and other characters, as well as some other more complicated claims.
In 1992, Congress passed a law to unseal all documents related to the investigation within 25 years.
Both Trump in his first term, as well as Joe Biden, released a large number of documents related to Kennedy, but thousands still remain partially or fully classified.
Trump’s executive order from two months ago also called on the Government Archives to unseal classified documents related to the assassination of presidential candidate Robert Kennedy and civil rights icon Martin Luther King. Both were killed in 1968.