It is the perfect complement to the Historical Society exhibition, which traces the circuitous routes that belatedly pointed Kennedy toward the more incendiary goals regarding civil rights, poverty and the Vietnam War that King set first.
Mr. Schiller and the show’s two other curators, Cristian Panaite and Marilyn Kushner, have assembled a selection of moving photographs of King and Kennedy (including some of Mr. Schiller’s own). Among the others on display are scenes eternalized by Bob Adelman, Danny Lyon, Henri Dauman, Jacques Lowe, Spider Martin, Steve Schapiro and Paul Schutzer: rapt audiences at campaign rallies and protest marches; speakers and their supporters animated with promise and dreams.
The images are jarring. As visitors follow the exhibition’s timeline toward 1968, only they — neither the speakers nor their faithful followers in the photographs — are haunted by the certainty that within months or weeks or days of the events depicted, two gut-wrenching murders would inevitably connect King and Kennedy even as their own dreams and promises were dashed.
Representative John Lewis, the contemporary of King and Kennedy as a young civil rights leader and now a Democratic congressman from Georgia, delivers a fitting joint epitaph: “When these two young men were murdered, something died in all of us,” Mr. Lewis says in the book. “We were robbed of part of our future.”
Mr. Schiller and Mr. Margolick, who met covering the O.J. Simpson murder trial in the mid-90s, had already been bound together themselves by a traumatic event that occurred in 1963, when Mr. Schiller was 26 and Mr. Margolick was 11: the assassination of Bobby’s brother Jack.
After growing up fearing Hitler and Stalin, Mr. Schiller said he was stunned that unspeakable evil could be committed by someone — the 24-year-old Lee Harvey Oswald — younger than himself. Mr. Margolick was imbued with such a mythical reverence for the slain president that no younger brother could possibly match his promise. To a preteen like Mr. Margolick growing up in suburban Connecticut, King’s association with civil rights confrontations that sometimes turned violent provoked misgivings.
Mr. Margolick, who in addition to being an author is a former reporter for The New York Times and a contributing editor at Vanity Fair, has made a career of delving into the stories of society’s victims. His books include “Elizabeth and Hazel: Two Women of Little Rock” and “Dreadful: The Short Life and Gay Times of John Horne Burns,” which challenged his own commitment to defending the rights of minorities.
“Those books were tests of my own character,” he said.
“The Promise and the Dream” was motivated by Mr. Margolick’s warts-and-all approach to biography and his personal need to reappraise King and Kennedy and their relationship. They were not only two people who happened to live at the same time. America demanded a myth that immortalized them inseparably.
They were indelibly bound together (with Lincoln and John F. Kennedy) by the fourth verse of Dick Holler’s bewildering folk-rock song “Abraham, Martin and John.” Kennedy’s tribute to King, delivered as he broke the news to an Indiana crowd of the civil rights leader’s assassination, was so poetic that both The Times and The Washington Post were seduced into advancing an enduring revisionist narrative that portrayed them as friends.
Except, they weren’t.
Kennedy, Mr. Margolick said, “saw King as a potential liability, particularly in the South.”
“King, while a supplicant, was still at the point where any connection to the white power structure was still a plus,” he said.
King, arguably, jeopardized his base by opposing the Vietnam War. Kennedy expanded his. He began to outgrow his long-held intolerance and insensitivity toward race, though he was baffled early on when a Harlem youth yelled “Gimme five,” thinking he was demanding money.
While he later became close to Cesar Chavez, the farm workers advocate, and other more radical civil rights leaders, he never invited King to his home. As attorney general, Kennedy approved the F.B.I.’s request to wiretap King and urged King to abandon the Freedom Riders, because their efforts were corroding the Democratic Party’s base in the South.
The book delves into this conflict. The exhibition does not. Instead, it emphasizes Mr. Margolick’s conclusion that King and Kennedy are “linked as no other black man and white man in the history of civil rights have ever been.”
“These guys were ascending to the same peak from different sides of the mountain,” he added.
The discerning observer will leave this exhibition recognizing a void: Mr. Schiller could not find a single photograph of King and Kennedy together (except in a group). They spoke by phone and met privately but, as Mr. Schiller said, “they didn’t want to be seen together.”
What might they say to each other 50 years later?
“They might laugh a bit together, and commiserate, over how careful they had to be with one another,” Mr. Margolick mused.
“They might even shake hands,” he said, “and smile for the cameras.”