Here’s an expression historian Patricia Sullivan has a problem with: post-racial.

“Post-racial is such an ahistorical term,” she argues one morning this week sitting at the window of a Vineyard Haven cafe.

“People don’t learn in school what this country is made from, and that’s fundamental to begin to have an intelligent discussion about what’s going on.”

The topic comes up in relation to an incident Ms. Sullivan would rather not publicly discuss, a recent altercation between members of the Cambridge police force and a Harvard professor who happens to be a colleague of Ms. Sullivan.

Nevertheless it’s entirely relevant to her book, Lift Every Voice, the first comprehensive history of the NAACP, published this month.

“For me as an historian, when I first came to [the history of NAACP], it changed my whole approach. As you get into it, you begin to see what you don’t know about American history, what you don’t know about America.

“And it invites you to just plunge in deep, learn, ask questions, read,” she says, with a laugh. “Then you won’t be talking about post-racial. That word will leave your vocabulary.”

Not that this should dissuade from striving for a racially equal society, she argues ­— after all, that is the impulse behind America’s progress thus far.

“As grim as it can be, people are always there facing it, pushing up against it, resisting it and changing it, and we all benefit from those struggles across centuries. People should be acquainted with who did it, how it happened and what the challenges are today.”

Ms. Sullivan, a New York native and seasonal Vineyard Haven resident, embarked on the story of the NAACP in 1999 at the tail end of the Clinton administration. In a combination of coincidences, the resultant book was published a decade later on the 100th anniversary of the founding of the NAACP and following the inauguration of the country’s first black president.

The stories Ms. Sullivan gleaned from material at the Library of Congress are legion. And though it was an almost imperceptible progress made over decades by the NAACP in sustained communal efforts, characterized by research and plodding case-building, there are plenty of incidents along the way which are the dramatic stuff of movies.

There is aptly named Walter White, the “blond-haired, blue-eyed Georgian” so fair skinned, she says, that he could “slip across the color line and move among white as if he were one of them.”

In the period directly following the first World War, writes Ms. Sullivan, when lynchings occurred at the rate of one per week, Mr. White assumed the role of intrepid reporter on behalf of the NAACP, posing as a salesmen or journalist for a white news organization to infiltrate mobs. He investigated the circumstances surrounding lynchings, uncovering the spurious triggers behind the torture and murder of blacks across America.

Mr. White’s reports were published in The Crisis, a magazine managed by W.E.B. DuBois, the renowned author, scholar and early key figure in the NAACP.

The magazine connected pockets of communities around the county, galvanizing support.

“These were tremendously creative people,” she said. “[The NAACP] attracted remarkable talent.”

Ms. Sullivan’s book is a catalogue of the organization’s feats of fund-raising, brilliant publicity coups and inventive legal work, all performed against a backdrop of gruesome, lawless violence and terror.

In 1946 in Lawrenceburg, Tenn., NAACP member Thurgood Marshall, who would later become the first black Supreme Court justice, won a case in connection with a recent riot in Columbia. Attempting to drive back to Nashville the following day, he was stopped three times by the police and eventually arrested on a bogus charge of drunk driving. He was carted off in a motorcade of angry policemen and, Ms. Sullivan believes, narrowly escaped being lynched.

“Marshall recalled that he ‘feared violence momentarily,’” she writes.

The work that Mr. Marshall did in Mississippi helped to lay the foundations for his Supreme Court victory in Brown vs. Board of Education of Topeka, which led to the desegregation of American schools. Mr. Thurgood led a team of NAACP lawyers who travelled the country in the 1940s arguing countless cases on voting, segregation, housing and transportation.

“These people continually risked everything. They had no protection,” she says. “The lesson is, political change doesn’t come from the top, it comes from people making a demand.”

In another story, one that doesn’t make her book, Ms. Sullivan illustrates that one of the major contributions of the NAACP was to instill belief in the possibility of progress.

“[NAACP lawyer] Robert Carter goes in to try a teacher’s salary case in Jackson, Mississippi in 1948,” she says, introducing another remarkable story.

During Mr. Carter’s case, the superintendent of schools called to the witness stand, perhaps confounded by being examined by a black person, began to ask Mr. Carter questions himself.

“Carter said, ‘No, no I am the lawyer, you’re the witness. I ask the questions, you answer them,’” she said.

The judge confirmed what was clear fact, and Mr. Carter continued the examination. Mr. Carter later heard that people reenacted the scene in barbershops and pool halls across Mississippi.

People would crowd in the courtrooms to watch the NAACP lawyers work, because it was a rare opportunity to glimpse black people working among whites as professional equals, says Ms. Sullivan.

“It was an important thing to hold on to, to see,” she says.

Disseminating the stories to as wide an audience as possible was the idea of Ms. Sullivan’s original editor, Joe Woods.

“We imagined it together. I’ll be forever grateful to him,” she says.

Mr. Woods was a young African American editor at the New Press when 10 years ago this summer he disappeared while bird-watching on Mount Rainier.

“He was the one who asked me to write this . . . he said, ‘I don’t want an institutional history. I want a book my parents will read, that will be on the coffee table next to Jet magazine,’” she recalls. “Now his parents, they’re reading the book. We’ll see if it gets on to the coffee table.”

Tonight, Friday, August 7, at 7 p.m. in the Tabernacle in Oak Bluffs, Ms. Sullivan will read extracts from her book and lead a discussion on the history of the NAACP and the civil rights movements, with guests Professor Charles Ogletree, Charlyane Hunter-Gault, Margaret Burnham and actor-director Clark Johnson, most recently seen on HBO’s The Wire.

General admission tickets are $15, available at the Martha’s Vineyard Museum, Alley’s General Store, Cousen Rose Gallery, and Bunch of Grapes Bookstore. A VIP reception with the author and panelists begins at 5:30 p.m. VIP tickets are $150 to benefit the Martha’s Vineyard Museum and include refreshments, preferred seating and a copy of the book.