AUSTIN (REUTERS).- The complete Pentagon Papers were made available to the public on Monday, exactly 40 years after leaked portions of the top-secret report on U.S. involvement in Vietnam were first published by the New York Times.

"There will probably be no smoking guns in this material, but for the first time it will be seen as it was created," Regina Greenwell, a senior archivist at the Lyndon Baines Johnson Library and Museum, told reporters.

"That is new -- looking at it in all its original form and in all its context."

The documents, stamped "declassified" in red, were wheeled out on a cart and unveiled at a press conference on Monday at the LBJ Library in Austin, one of several places where researchers can now view them.

They're also available at the John F. Kennedy and Richard M. Nixon presidential libraries, at the National Archives in College Park, Maryland, and online on the National Archives website.

The 7,000-page report was commissioned in 1967 by Secretary of Defense Robert McNamara. About 34 percent of the report became available for the first time on Monday, according to the National Archives. The rest had already been leaked or released in one form or another.

McNamara believed the study would help future generations avoid mistakes made in Vietnam, Henry Trewhitt wrote in "McNamara: His Ordeal in the Pentagon."

"When its contents broke in the press, however, his pleasure at seeing the record clarified was badly diminished by his shock that the two administrations (Kennedy and Johnson) had been deceitful about escalating the war," Trewhitt wrote, although McNamara served under both men.

Johnson had pushed for the release of the Pentagon Papers and other Vietnam War documents, according to Harry Middleton, a Johnson speechwriter who directed the LBJ Library for 30 years.

"He had the feeling, right or wrong, that when everything was made available and it was all laid out on Vietnam, history was going to understand the reasons for the critical decisions that were made," Middleton said in a video posted on the LBJ Library's website.

Middleton said Johnson's reaction to the release of the papers after so many years would have been: "What the hell took so long?"

http://www.archives.gov/research/pentagon-papers/

(Editing by Jerry Norton)