Nearly a decade after retiring in 1969 from his illustrious career coaching football at Florida A&M University, Jake Gaither placed his gridiron efforts into a broader frame of racial pride and identity. “For a Black boy, this is not just a game of football,” he told George E. Curry, the journalist who wrote Gaither’s authorized biography. “He is carrying a cross of fifteen million Blacks on his shoulders.”

In multiple ways, Gaither made football at the historically Black school into a potent force in the battle for racial equality. He produced more pro players than many of the all-White football factories of the Southeast Conference. He cracked the segregation barrier in Tallahassee by attracting White and Black coaches together to his annual coaching clinic. In his final game as head coach, he led his Rattlers to victory over the University of Tampa in the first college football game in the Jim Crow South between an all-Black and a predominantly White team.

Nor was race the only arena for using college football, with its immense popularity and its teamwork ethos, to strike a blow against bigotry. As the sports historian Jim Lefebvre recounts in his two fine books about Notre Dame during the Knute Rockne era — “Loyal Sons” and “Coach for a Nation” — the famous coach very consciously promoted his Fighting Irish teams nationally to counter the anti-Catholic hatred that burgeoned in the 1920s.

In this tradition of football as a vehicle for social change, which that began long before Colin Kaepernick’s courageous activism in the present day, Bradford Pearson has uncovered an absolutely stirring story in his rigorous and important, though flawed, new book, “The Eagles of Heart Mountain.” The high school football team of Pearson’s title was entirely composed of Japanese immigrants and Japanese American citizens who were essentially imprisoned in remote camps during World War II on the specious belief that they might be traitors or terrorists.

With admirable ambition, Pearson seeks to use the Eagles’ exploits as a compelling and accessible through-line for a deep inquiry into Franklin D. Roosevelt’s odious decision in Executive Order 9066 to intern 120,000 people of Japanese ancestry. Pearson is entirely right to reject the euphemisms of “internee” and “internment camp” in favor of “incarceree” and “concentration camp.”

In his narrative, Pearson most closely follows Tamotsu Nomura and George Yoshinaga, who had been playing on mostly White high school teams in California when their families were rounded up. Both young men starred in the Eagles’ first season in the Heart Mountain Relocation Center in Wyoming, during the fall of 1943, and after graduating from high school served as a coach (Nomura) and a sportswriter for the center’s newspaper (Yoshinaga) in the Eagles’ 1944 campaign. Within the realm of football, these falsely accused and unconscionably punished athletes went by the nicknames of their earnest, endangered Americanization — “Babe” and “Horse,” respectively. Their Eagles won six of the seven games they played over two seasons, despite having no player heavier than 175 pounds and only three who had previously played high school football.

A veteran magazine editor and writer, Pearson correctly surmises that many of the readers drawn to a book about football will never have encountered the substantial literature and scholarship on Japanese American incarceration, from Richard Reeves’s authoritative history, “Infamy,” to Julie Otsuka’s novel about one family, “When the Emperor Was Divine,” to the anthology “Only What We Could Carry.”

So Pearson wisely wants to situate the Eagles within the broader context of anti-Japanese racism before and during the war. The problem is that the context crowds out the primary story line. Though a reader meets Nomura and Yoshinaga in the first several dozen pages of the book, and though they intermittently reappear amid the lengthy historical portions, they slide too much into the background until the riveting final third of the book. That is a long time for a book of narrative nonfiction to go without focusing on its protagonists.

To his credit, Pearson has done prodigious research on the bigoted path toward incarceration, and his cast of villains includes not only FDR but other putative liberals — Earl Warren, who supported removal of Japanese Americans as both attorney general and governor of California, and Karl Bendetson, a lawyer who was a grandson of Eastern European Jewish immigrants. Walter Lippmann, the influential journalist, devoted one of his syndicated columns to whipping up fear of “The Fifth Column on the Coast.”

But the sheer volume of historical background in “The Eagles of Heart Mountain” buries its most singular material. And, even on its own terms, the contextual chapters suffer from disorganization, looping forward and back in time in a disorienting way.

For the readers who persevere to get there, and hopefully most of them will, the last 100 pages brilliantly combine an underdog football tale with an account of the protest movement mounted by Heart Mountain’s imprisoned innocents. Sixty-three men from the concentration camp were arrested and found guilty of resisting the draft after the Roosevelt administration found it expedient to throw the very people it persecuted onto the wartime front lines for the United States.

“We are not being disloyal,” declared an activist group at Heart Mountain called the Fair Play Committee. “We are not evading the draft. We are all loyal Americans fighting for JUSTICE AND DEMOCRACY RIGHT HERE AT HOME.”

Those words sound every bit as timely and urgent in today’s nexus of sports and social justice, and it is thanks to Pearson’s deeply felt book that we now know them.

The Eagles of Heart Mountain

A True Story of Football, Incarceration, and Resistance in World War II America

By Bradford Pearson

Atria. 373 pp. $28