WASHINGTON — (CNN) In 1961, the CIA debuted a new type of confidential intelligence report for President John F. Kennedy, a daily morning briefing surveying the threats facing the country so top secret that it was kept even from his second-in-command.

The CIA says it was directed that “under no circumstances” should it be delivered to Vice President Lyndon B. Johnson, likely due to political rivalries between the two.

The detail is just one of many surrounding the key intelligence briefing the President receives each morning — known first as the President’s Intelligence Checklist, abbreviated as PICL, and then later as the President’s Daily Brief, or PDB — that were shared in the CIA’s declassification Wednesday of an unprecedented number of documents related to the briefing book.

The 19,000 pages of released briefings contain details of the Cuban Missile Crisis, the erection of the Berlin Wall, the Tet Offensive and other major events that shook the Kennedy and Johnson presidencies from 1961-1969. Portions of the briefs still remain redacted.

Despite the seriousness of the topics, the intelligence points were written to be highly casual, calling details, for example, “sketchy” and, in one instance, describing a Polish ambassador who defecated on himself after being trapped in a car.

“A mob kept the Polish ambassador in his car for 10 hours, causing him to ruin both his clothing and the upholstery,” the brief states. This language is radically different than the formal briefs President Barack Obama receives today, according to the CIA.

More serious information included the steady uptick in Soviet military capabilities in Cuba as part of the Cuban missile crisis.

“(M)ore SAM (surface to air missile) sites along the north coast,” the brief reads on Oct. 9, 1962. “They will close one of the few remaining gaps in missile coverage of the island.” Two days later, the briefing refers to “two more surface-to-air missile sites, making a total of twenty. At least some, possibly many of these sites could now be operational, but we are not sure of this yet.” Then an additional missile site is discovered more than a week later. Oct. 23, 1962: “We can now account for 33 missiles and 23 launchers.”

One note from that initial brief detailed “Soviet ICBM shot aborts” and informed Kennedy that an intercontinental ballistic missile test “either failed immediately after launch or was canceled at the last minute.”

Just a couple of months later, the PICL documents the initial steps taken by communist East Berlin to build the Berlin Wall that would separate it from West Berlin. On Aug. 17, 1961, a section of the report titled “The Situation in Berlin” details “floodlights” being installed, along with “mazes of concrete stanchions and permanent fences.”

The President’s Daily Brief was born under the Kennedy administration in June of 1961, when President Kennedy saw the need for a single intelligence product after the failed Bay of Pigs invasion of Cuba earlier that year. The administration’s concern was there were too many different intelligence reports that lead to important information being missed.

In a 1998 internal CIA interview with the document’s creator, Richard Lehman, Lehman said he was asked by the Kennedy administration to create “something that will have everything in it that is worth the President’s attention,” with the specification that it “fit it into a breast pocket so that the President could carry it around with him and read it at his convenience.”

Kennedy only received the briefs that were initially created for him for two years before being assassinated on Nov. 22, 1963. On that day, the PICL was dedicated to Kennedy. “For this day, the Checklist Staff can find no words more fitting than a verse quoted by the President to a group of newspapermen the day he learned of the presence of Soviet missiles in Cuba,” the page reads. “Bullfight critics ranked in rows Crowd the enormous plaza full; But only one is there who knows And he’s the man who fights the bull”.

Johnson was updated with information on Kennedy’s killer, Lee Harvey Oswald, three days after Kennedy’s assassination. The PICL confirms press reports that Oswald traveled to Mexico City, where he visited both the Cuban and the Soviet embassies on September 28, 1963. “He was trying, we are told, to arrange for visas so that he could travel to the USSR via Havana. He returned to the US on 3 October.”

The PICL was replaced by the President’s Daily Brief in 1964, a year after Kennedy was assassinated and Johnson’s term began.

Lehman recalled in the CIA interview that it “didn’t appeal to him (Johnson) the way it did to Kennedy” and described Johnson as “not that much of a reader.”

But the CIA retooled the document in part to catch Johnson’s attention and separate the report from what Johnson viewed as a Kennedy product, renaming it the President’s Daily Brief.

The document had been initially called the President’s Intelligence Checklist, abbreviated as PICL, and pronounced the “pickle.” The first PICL contained 14 short intelligence briefs that were complimented by notes and maps.

The PDB was similar to the PICL in its concise points on national security issues, but it went further with longer one- or two-page analyses on certain topics. The new brief was a success and was said to have been read “avidly” by Johnson.

By 1968, Johnson read about the Vietnam War almost daily, with attacks by North Vietnam on the south, known as the Tet Offensive, playing prominently in the reports. At the beginning of the wave of attacks, on Jan. 30, 1968, the PDB chronicles “sharp fighting” that seems to catch the intelligence agencies off-guard.

“Information is still sketchy on what is happening around the other cities and bases hit by the well-coordinated and unprecedented Communist offensive,” reads the briefing. “Designed for maximum psychological impact, the Communists concentrated on showing they could shoot their way into major populated areas, particularly provincial capitals.”

Mentions of the Soviet Union dominated the documents, showing up in 80 percent of the briefings over that period. Intelligence reports on Vietnam followed in importance, with mentions in 70 percent of the briefings. During the Johnson administration, developments in Vietnam were reported on almost daily and peaked in 1965 after the U.S. began an extensive bombing campaign in North Vietnam and again in 1968 with the Tet Offensive, when North Vietnam launched a series of attacks against the South.

Publishing the daily briefings was a 24-hour process and still is today. President Kennedy liked to read the brief at his desk when it arrived at the White House in the morning. President Johnson initially preferred to receive the PDB late in the afternoon so he could read it in bed. He later asked to see the PDB at 6:30am before he began reading the morning newspapers. Unlike today, the CIA did not brief the president on the intelligence document; instead, Kennedy and Johnson were normally briefed by senior members of the National Security Council, in most cases the national security advisor.

Today the PDB is delivered using a secure mobile device and includes interactive links with video features and other multimedia components. Obama receives the PDB on a tablet.

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