AUSTIN (AP) – Precisely 40 years after they began to appear in The New York Times, triggering a constitutional crisis over freedom of the press, the Pentagon Papers will be released at the Lyndon B. Johnson Library and Museum and other sites Monday.

Officials with the Lyndon B. Johnson Library on the University of Texas at Austin campus have scheduled a news conference to unveil the once-top secret, 7,000-page Pentagon study of the Vietnam War first leaked to The New York Times. Simultaneous releases of the papers also are planned at the John F. Kennedy Library in Boston; Richard Nixon Library in Yorba Linda, Calif.; and the National Archives at College Park, Md.

The Times began publishing the documents 40 years ago until a federal judge halted the publication. A fragmented U.S. Supreme Court struck down the ruling. In the meantime, The Washington Post published the documents.

The release also comes 38 years after President Johnson himself asked Nixon, his presidential successor, to release them to the public, the Austin American-Statesman reported Sunday. Johnson died 10 days later of a heart attack.

The LBJ Library has had a complete set of the report documents since 1969. Former Johnson aide Tom Johnson said the documents leaked to The Times and The Post did not include a section about secret Johnson administration efforts to negotiate peace with North Vietnam.

Former Johnson aide and past LBJ Library director Harry Middleton said Johnson’s response to Monday’s release would have been, “What the hell took so long?”

“He felt, to get the whole story out, that everybody should have access to the papers in the LBJ Library,” Middleton told the American-Statesman.

Another former Johnson aide, Tom Johnson, who was not related to his former boss, said, “He felt his decision-making about Vietnam could withstand full scrutiny.”

Middleton said that Johnson phoned him at the library to complain when the leaked Pentagon Papers were published in 1971.

“This is only part of the story. They don’t have the whole story,” Middleton recalled Johnson telling him.

Johnson and his aides began building their case to present to Nixon for release of the papers. Middleton said he attended a dinner party at the LBJ Ranch on Jan. 13, 1973, where Johnson told him he wanted a face-to-face meeting with Nixon to seek declassification of the documents.

“I’m going to do that as soon as President Nixon is inaugurated,” Middleton recalled Johnson saying. “I’m going to go to Washington and take it up with him.

Nixon was inaugurated a second time a week later, but Johnson died two days later without having the meeting. Johnson aides and associates continued talks with Nixon counterparts in hopes of getting the documents declassified, but nothing happened until the Watergate scandal ended all discussions of the topic.

“President Johnson insisted that the full story of his presidency should be available to historians, authors, scholars, researchers and especially students,” Tom Johnson said. “It always was LBJ’s mandate to release all the papers, provided no intelligence-gathering methods or secrets about sources were disclosed.”

Indeed, 11 words of the finally declassified history of U.S. involvement in Vietnam will remain secret. The National Declassification Center will only say that the 11 words are all on one of the work’s 7,000 pages.

(© Copyright 2011 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)