President Trump released documents Thursday night about President John F. Kennedy's 1963 assassination.
According to the documents, someone called the FBI and threatened to kill Lee Harvey Oswald one day before he was killed.
They documents also say the CIA considered putting mafia hits on Cuban President Fidel Castro.
The government kept many documents classified because of national security.
President Trump ordered government agencies to consider releasing more documents in 2018.
The President wants a review done in the next five months.