He was a key player in some of the most traumatic and glamorous events in American history. He was also a hoarder.

And so on Tuesday, Sotheby’s will begin previewing an auction of extraordinary items left behind by Robert S. McNamara, secretary of Defense under Presidents John F. Kennedy and Lyndon B. Johnson.

The stash, culled from a storage room in McNamara’s Watergate apartment, includes an eclectic mix of items, stretching from a boyhood in California to the dazzling White House years and the tumult of the Vietnam War: intimate handwritten letters from Jackie Kennedy; notes from and photos of JFK and RFK and LBJ; a cache of medals; an Eagle Scout badge from 1933; the flag from McNamara’s Pentagon office; his colorful Presidential Medal of Freedom; and much more.

The preview is targeted to coincide with the 50th anniversary the Cuban Missile Crisis, when the U.S. and Soviet Union supposedly stood at the brink of a nuclear confrontation—and McNamara, as defense secretary under JFK, played a key role in guiding the White House strategy. Sotheby’s exhibition will last 13 days, just as the missile crisis did, before the auction begins on Oct. 23.

Executives at Sotheby’s are “thrilled” to land such a rare and exclusive trove. “It’s a close as you can get to memorializing history. I think our clients will be amazed by the type and personal nature of the material that is available,” says David Redden, vice chairman of the auction house.

But this sale, like so much of McNamara’s life, is not without controversy.

It has stirred up a certain amount of angst among his friends and family, who are surprised and dismayed that so many of his private possessions are now on the block. The artifacts were assembled and consigned by his second wife and widow, Diana, without any consultation or advance notice to his three children from his first marriage.

They had requested a few objects for themselves and their children, they say, and only learned about the actual contents of the auction from friends and the glossy catalogue: “The White House Years of Robert S. McNamara.”

“Our father’s will left all of our dad’s tangible personal property to his second wife. His children played no part in her decision to sell the memorabilia,” they tell The Daily Beast.

Diana McNamara, a vivacious Italian who divides her time between Middleburg, Va., and Washington, married the late cabinet secretary in 2004, five years before his death.

She declined to be interviewed, referring instead to her preface in the catalogue, which extols her husband’s illustrious career from Harvard “whiz kid” to the head of the Ford Motor Company to the heights of Camelot and on to president of the World Bank. Her salutation reads, “Robert S, McNamara—revered, praised, questioned, respected, honored, celebrated … and loved.”

(An interesting note: When McNamara accepted the president-elect’s offer, only six weeks after assuming the reins at Ford, he laid out his own rules for running the Pentagon and at 45 became the youngest secretary of defense. His salary instantly plunged from $400,000 to $23,000.)

The lynch pin of the whole collection, according to Redden, is a handsome Tiffany walnut and silver paper weight/calendar inscribed with the initials of Kennedy and McNamara. It is a gift from the president to highlight and commemorate those 13 suspenseful days of the Cuban Missile Crisis—Oct. 16 to Oct. 28, 1962.

Equally intriguing is Jackie Kennedy’s affectionate letter to McNamara of Oct. 25 describing, in her spidery script, the commotion in the executive mansion during that chaotic period.

“You must be very tired—I cannot find the right ways to say all the things I feel. I am so proud of you and grateful you are here … Please know that is not said as Jack’s wife—but just as a plain person. For awhile I felt that I really knew what was going on—but that lovely illusion has evaporated … So this ends up being just one more letter from the man in the street—or as I am no longer allowed to go into the street—the girl in the driveway. But please do not laugh at it. I had to tell you of my admiration—and I do thank God you are here.”

The number and breadth of these tender notes from the first lady to McNamara are stunning. Many close, “With all my love,” or a series of xxs and oos, as he evolved into one of her most trusted confidants and advisers.

According to Sotheby’s, these remarkable letters, many written on thin, lilac or baby blue paper, are the most significant assemblage of Jackie’s personal White House and post-White House correspondence to have come on the open market. The auction house predicts a groundswell of attention.

Her missives cover a broad range of topics: the grave site for the president (McNamara suggested Arlington); stopping the Vietnam War; her frustration with Harvard over the Kennedy Library; art; literature; valentines; even one of her own sketches, a humorous watercolor of a tiger. Throughout the years McNamara remained a stalwart in her life and her devotion never wavered. On occasion she dubbed him her “knight in shining armor.”

“The exhibition is already creating buzz,” says Selby Kiffer, senior vice president of books and manuscripts. “We’ve had inquiries from potential bidders all over the country.”

And though no one anticipates a blockbuster, expectations are set for a competitive auction with “surprisingly high prices.” There are no comparisons because the collection is unique.

There is also a more than flurry of interest in an assortment of other documents and items, ephemera of the Johnson era including presidential signing pens and inaugural tokens, along with North Vietnamese propaganda, notes on the text for McNamara’s appearance in the Oscar-winning documentary The Fog of War, plus a raft of negative political cartoons about him, warmly inscribed by the individual cartoonist.

Through what Sotheby’s refers to as “the magic of the auction process,” the complex private life of a public man is about to be turned into an event, a happening, accessible to the highest bidder.