Years before the NBA smashed the color barricade, a couple of North Carolina college basketball teams quietly integrated the sport in a secret, dramatic game.

On March 12, 1944, Duke University Medical School basketball players — white men, all — drove across Durham, N.C., to meet up with players from the North Carolina College of Negroes. They deliberately chose a quiet time of day, and they draped their car windows with blankets so that no one could see inside.

This was a dangerous, even deadly, undertaking. In those years, the Ku Klux Klan was powerful; members considered “race mixing” immoral, punishable by death. The game had to be played in utter secrecy.

This historic basketball game is the subject of John Coy’s latest picture book, “Game Changer,” published last month by Carolrhoda Books/Lerner Publications of Minneapolis.

“It was an incredible story,” Coy said, one he was drawn to because of the courage of the men who took part. “I wanted more people to know about these men and what they had done.”

It was while he was researching a previous book, “Hoop Genius,” that Coy grew interested in the story of a coach named John McLendon.

“He was just an amazing guy,” Coy said. “He had won three consecutive national championships, and he was the first African-American to coach at a white college. I thought it was really strange that someone with his accomplishments is not better known.”

And then he remembered reading years ago about the Secret Game. He did a little research to find out who had been behind it.

John McLendon. Same guy.

Coy had his next book.

The research for “Game Changer” took years. While most people might think of picture books as whimsical tales with gorgeous pictures, nonfiction picture books have been a growing part of the children’s book market for more than 10 years. The research that goes into them can be prodigious.

“Because of the brevity, you have no hope of being comprehensive, but that’s not part of the job,” said Andrew Karre, Coy’s editor at Carolrhoda (and now an editor at Dutton Books). “The job is for the author to pick a moment. To do that, you have to leave a ton out, but you have to know it all.

“A truly accomplished picture book is like a sonnet. You start with a block of marble and you pare it down to the statue.”

It takes “a ton of research,” Coy agreed. “That’s the nature of these nonfiction projects. Then the challenge is how concise to make it.”

With “Game Changer,” two years of research were distilled into 800 words.

Coy, 57, who lives in Minneapolis, has written 16 books — picture books, middle-grade books and young-adult novels. He has been part of COMPAS writers and artists in the schools for 20 years, traveling the state and talking to kids about writing and books.

As a child growing up in Eau Claire, Wis., “I never even thought about becoming a writer,” he said. “It was not even in the realm of possibility. I loved reading, loved books, but I grew up with the idea that they came from somewhere far away. My entire time as a student, we never once had an author visit us.”

The lessons of his school visits go both ways: He shows students his tortured and scribbled first drafts, letting them know that writing is hard for everyone, even authors. And the students remind him how the state is changing, growing more diverse by the year, and also how times (and pop culture) are changing.

Coy doesn’t write for any particular audience — plenty of adults, he said, have been drawn to his books, as well as plenty of girls — but he’s particularly aware that, historically, it has been harder for boys to find books that interest them.

“I think this whole new emphasis on nonfiction is partially a way to get more boys involved,” he said. “A lot of them really like nonfiction. We can tell really good stories in nonfiction.”

In “Game Changer,” each detail is true. The furtive drive. The blanketed windows. The all-white team, the all-black team. The final score of 88-44. The winner — well, we won’t reveal that here, but that, too, is a historical, verifiable fact.

“A lot of kids ask, ‘Is it true?’ And when they find out it’s true they find there is a little special connection,” Coy said. “That’s the joy of nonfiction. When they like a story, they can go find more about it.”

And on the last page of “Game Changer,” Coy, in his selected bibliography, helps them do just that.