As historians pored over details included in the 2,800 files that were released to the public, some were disappointed that potentially insightful information may be among that still being withheld at the request of the US intelligence community.

In addition to files relating to Oswald’s six-day trip to Mexico, information about Dallas businessman Gordon McClendon, a radio station owner who is said to have spoken to Jack Ruby, shortly before he shot and killed Oswald two days after John F Kennedy’s assassination, was not made public. The Washington Post said government files about infamous anti-Castro Cuban exiles, including Luis Posada and Orlando Bosch – accused of the 1976 bombing of a Cuban airline – were similarly not released.

In advance of the release of the files, Mr Trump had vowed transparency and suggested he wished to make public all of the estimated 3,100 files relating to the assassination of the US’s 35th president held in the National Archives. As it was, around 2,800 were released, with the remainder being withheld for a further six months at the request of the US intelligence community.

A government official told reporters most of the files being retained belonged to the CIA and FBI. Mr Trump was said to have been disappointed he could not make all of them public and there was speculation the agencies were acting intentionally after the President made accusations towards them after he was elected.

On Friday morning, he repeated his hope to release all the available information. “JFK Files are being carefully released. In the end there will be great transparency. It is my hope to get just about everything to public,” he said on Twitter.

What are the JFK files?

In a statement accompanying the release of the documents, Mr Trump said: “Departments and agencies have proposed to me that certain information should continue to be redacted because of national security, law enforcement, and foreign affairs concerns. I have no choice – today – but to accept those redactions rather than allow potentially irreversible harm to our nation’s security.”

Among the documents that were released are those that capture the frantic mood of the country in the days after the assassination of the 46-year-old president, as officials sought to discover whether Oswald was working alone or as part of a broader conspiracy.

The assassination of JFK – in pictures Show all 8 1 /8 The assassination of JFK – in pictures The assassination of JFK – in pictures President John F. Kennedy and his wife Jacqueline Kennedy ride with secret agents in an open car motorcade shortly before the assassination, 22 November 1963 Getty The assassination of JFK – in pictures President John F. Kennedy and his wife Jacqueline Kennedy prior to his assassination Keystone/Getty The assassination of JFK – in pictures Kennedy is struck by an assassin's bullet as he travels through Dallas in a motorcade In the car next to him is his wife Jacqueline and in the front seat is Texas governor John Connally Three Lions/Hulton Archive/Getty The assassination of JFK – in pictures The view from the sixth floor window of the Texas School Book Depository in Dallas, from which Lee Harvey Oswald is thought to have assassinated Kennedy. This photograph was taken approximately one hour after the assassination Hulton Archive/Getty The assassination of JFK – in pictures Lee Harvey Oswald during a press conference after his arrest in Dallas. Lee Harvey Oswald was killed by Jack Ruby on 24 November on the eve of Kennedy's burial AFP/Getty The assassination of JFK – in pictures Lyndon B. Johnson takes the oath of office as President of the United States on the day of Kennedy's assassination. Jackie Kennedy is stood next to Johnson Getty The assassination of JFK – in pictures Kennedy's funeral procession goes into Arlington Cemetery in Washington Newsmakers/Getty The assassination of JFK – in pictures Kennedy's casket sat in the East Room of the White House Newsmakers/Getty

A memo believed to have been dictated by FBI Director J Edgar Hoover on 24 November 1963, two days after the assassination and the day that Oswald was himself shot and killed, started: “There is nothing further on the Oswald case except that he is dead.”

Later, Hoover recognised that many would not believe that Oswald had acted alone – something that has proved true.

JFK and his wife Jackie ride in the motorcade shortly before his assassination (Getty)

“The thing I am concerned about, and so is [deputy attorney general] Mr Katzenbach, is having something issued so we can convince the public that Oswald is the real assassin,” he said in one note, according to the Associated Press.

He added: “Last night we received a call from our Dallas office from a man talking in a calm voice and saying he was a member of a committee organised to kill Oswald.”

Hoover said he passed on the warning to the Dallas police and was told Oswald would be sufficiently protected. As it was, Oswald was shot dead the next day by Ruby.

An FBI cable from April 1964 recounts part of Oswald’s bus trip to Mexico in October 1963, including the names of the people sitting around him.