In 1968 she wrote a book, Kennedy and Johnson in which she wrote that President Kennedy had told her that Lyndon B. Johnson would be replaced as Vice President of the United States. Lincoln wrote of that November 19, 1963 conversation, just before the assassination of President Kennedy,
As Mr. Kennedy sat in the rocker in my office, his head resting on its back he placed his left leg across his right knee. He rocked slightly as he talked. In a slow pensive voice he said to me, 'You know if I am re-elected in sixty-four, I am going to spend more and more time toward making government service an honorable career. I would like to tailor the executive and legislative branches of government so that they can keep up with the tremendous strides and progress being made in other fields.' 'I am going to advocate changing some of the outmoded rules and regulations in the Congress, such as the seniority rule. To do this I will need as a running mate in sixty-four a man who believes as I do.' Mrs. Lincoln went on to write "I was fascinated by this conversation and wrote it down verbatim in my diary. Now I asked, 'Who is your choice as a running-mate?' 'He looked straight ahead, and without hesitating he replied, 'at this time I am thinking about Governor Terry Sanford of North Carolina. But it will not be Lyndon.'
According to the National Archives, Lincoln gave away or sold many of Kennedy's documents and artifacts that she had been entrusted to collect after Kennedy's assassination. In 2005, a legal settlement was reached that enabled the National Archives, the Kennedy Library, and Caroline Kennedy to recover thousands of pages of documents and other items that had been improperly sold or given away by Lincoln.
James M. Roth, Reclaiming Pieces of Camelot: How NARA and the JFK Library Recovered Missing Kennedy Documents and Artifacts, Prologue Magazine, Summer 2006, Vol. 38, No. 2.