Wil Haygood is the Boadway Distinguished Scholar-in-Residence at Miami University, Ohio, and the author, most recently, of “Showdown: Thurgood Marshall and the Supreme Court Nomination that Changed America.”

In the early 1960s, America was alternately beguiled and frightened by the urgency of demands for equal rights from its black citizenry. Attempts to register to vote, to integrate colleges and universities, to become part of the American Dream, as it were, often resulted in bloodshed. The news footage of the clashes — against the backdrop of state-sanctioned segregation — shocked the world.

Malcolm X and Muhammad Ali were two of the marquee figures from that fire-next-time era. Both were in the vanguard of black independent thinkers who shook up a host of people and institutions, among them J. Edgar Hoover’s FBI, local police departments and mainstream society. They talked of racism in raw terms. They even made some blacks of a conservative bent quite nervous. Being denied the vote might give way to bullets, Malcolm X ominously intoned. As for Ali — who changed his name from Cassius Clay in 1964 — he pronounced he would not abide by the military draft. These were not men with the patience to wait for justice.

Randy Roberts and Johnny Smith’s “Blood Brothers” tells the story of these two galvanizing and hypnotic personalities and of the America that produced them. Although the book promises more than it delivers, it is earnest and, by focusing mostly on the years between 1962 and 1965, smartly constructed.

Family dysfunction lay in the upbringing of both men. Cassius Clay Sr. was a mean and petty man who beat his wife. The younger Clay — feral, handsome and loud — was a star in the Louisville boxing scene who wanted to get away from his father. He brought home a boxing medal from the 1960 Rome Olympics and began to find it harder to swallow that he must still dine in segregated restaurants.

"Blood Brothers: The Fatal Friendship Between Muhammad Ali and Malcolm X" by Randy Roberts and Johnny Smith (Basic)

Earl Little was Malcolm’s father. His life came to a gruesome end in 1931 in Lansing, Mich., after a streetcar accident. Did he really slip beneath the streetcar? Blacks scoffed, believing it foul play at the hands of whites. Earl Little was a black nationalist, a follower of the teachings of Marcus Garvey and a man who unsettled many Lansing whites. “One man was scarred by his father’s absence,” the authors write, “the other by his father’s presence.”

Young Malcolm, fatherless and restless, became a thief, a pimp and a convict, entering a Massachusetts prison in 1946, where he would remain for six years. Once out of prison, Malcolm X — who had found Islam behind bars — became a rising star in the Nation of Islam, steadily promoted by Nation of Islam leader Elijah Muhammad.

The young Clay, entering the ranks of professional boxing, became intrigued with the Nation of Islam. Its teachings and guidance began to salve his wounds of second-class citizenship.

There was something at ground level that seemed to intertwine the sport of boxing and religion. “Both worlds — boxing and the Nation of Islam — demanded physical fitness and a purity that rewarded resistance to temptation,” the authors note.

If the morphing of Cassius Clay into Muhammad Ali needed a final push, the stardom of Malcolm X seemed to provide it. Malcolm was leading protest marches through an assortment of major cities. He was claiming headlines and gathering followers. Elijah Muhammad, whose presence hovers over this book like Mephistopheles, treated him like a son. “My hobby is stirring up Negroes,” Malcolm had said.

The prizefighter first met Malcolm X in Detroit: the young lion and the older lion, both trying to figure out how to tear at the bone of racism. “My first impression of Malcolm X,” the boxer confided, “was how could a black man talk about the government and white people and act so bold and not be shot at?”

Soon enough, politics and Malcolm X’s growing dismay over Muhammad’s serial infidelities give way in this narrative to Clay’s boxing prowess. In 1964 the underdog Clay — fond of spouting silly and rhythmic poetry in pre-bout press gatherings — fights Sonny Liston and takes his first championship belt. He is world champion; he is “king of the world”; he is now Muhammad Ali, a converted Muslim for the world to see.

The authors are good at chronicling the sportswriters, mostly white men, who belittled Ali for his religious decision and political awakening. This was not an apolitical Joe Louis-like figure, and the sportswriters found it hard to adjust.

The narrative tightens considerably as Malcolm X becomes despondent about Muhammad’s affairs. Children are born out of wedlock, infuriating Malcolm. His inquiries into Muhammad’s personal life are considered an insult by the Nation of Islam leader.

When President John F. Kennedy is assassinated, Nation of Islam officials are ordered by their leader to say nothing that would deepen the country’s hurt. Malcolm X believed that Kennedy had had a role in the murders of South Vietnamese President Ngo Dinh Diem and Congolese Prime Minister Patrice Lumumba. He also felt the president didn’t respond vigorously enough to violence against blacks in the South. Malcolm X ignored the Nation of Islam directive and told the press that Kennedy’s killing was an example of “the chickens coming home to roost.” The comment infuriated many, especially Muhammad, who silenced Malcolm X, forbidding him for a period to speak on behalf of Muslims in the country.

Malcolm X — the fissures between him and the Nation of Islam deepening — took a pilgrimage to Mecca, coming back a changed man. He softened his fiery rhetoric. He intended to work with integrationists and mainstream civil rights leaders. He desperately reached out to Ali, wanting him to understand, hoping that Ali would distance himself from the philandering Muhammad. Ali would not.

In mid-February 1965, Malcolm X’s home was firebombed, but the family escaped injury. On Feb. 21, Malcolm was gunned down while delivering a speech in Harlem, the murderous deed carried out by fellow Muslims.

Because their face time in life was actually rather limited, there is not quite enough here to convince one that Malcolm and Ali were “blood brothers.” They were, true enough, figures in the brewing ferment of politics, sports and race, rather quickly enmeshed in a splintering, colossal family feud. But there is enough here to make one appreciate the dynamism of both men, whose reputations have undergone transformations, leaving both as fuller and more dimensional figures in the American mind-set.

Blood Brothers
The Fatal Friendship Between Muhammad Ali and Malcolm X

By Randy Roberts and Johnny Smith

Basic. 362 pp. $28.99