Kevin Baker hails a cab and we ride uptown to the setting of his new novel about Harlem in the riotous 1940s, Strivers Row, out from HarperCollins this month. As we move past 125th Street, the winter sky threatens rain. Baker, curly-haired, bespectacled, looks through the window and calls out faded WWII-era landmarks: the Alhambra Ballroom, the Renaissance Casino. "Oh," he says, pointing at an enormous International House of Pancakes, "this is where Small's Paradise was."

A few minutes later, we're standing in front of the massive stone-and-glass exterior of the Abyssinian Baptist Church on 138th Street. The church's real interiors, Baker tells me, were the model for the fake church in Strivers Row, and the real passing games played by the Abyssinian's real minister, the fair-skinned African-American charmer Adam Clayton Powell Jr., inspired the fake passing games played by Baker's fake minister, Jonah Dove.

We walk over to gaze at the beautiful 1890s brownstonesof the real Strivers Row where Jonah's fake house would be located, that is, if it ever had existed at all. What about the black singer who passes for a dirty white girl, I ask. Was she for real? No, she was inspired by Clayton Powell's sister. And that Jewish department store where Jonah meets a Polish refugee? It's a parody of Blumstein's, once Harlem's finest department store.

As we stroll around the neighborhood and I pepper him with questions, Baker doesn't break a sweat. He's confident about which events constitute Harlem's real history, and which are his inventions. Op-ed pages are still aboil with writers disputing what constitutes truth, fiction, memoir and autobiography, but Baker, unlike many, can relax: his career, as a respected historian and a bestselling novelist, stands as an example of how working in one genre can enrich an author's performance in the other—without the writer ever confusing the two.

Though he's now known as a New York novelist, Baker, 47, grew up in Massachusetts. When he arrived in Manhattan in 1976 to study at Columbia College, he was ready to dedicate his life to fiction. "I was there at my typewriter doing five pages a day, certain that I was going to sell a novel before I was out of college," he recalls with a laugh. "But it was the classic problem—I had nothing to write."

In fact, it would be 15 years and half a dozen post-college jobs before Baker sold a word of fiction. To support himself, he worked any freelance job he could. He compiled data for the Foundation Center (where he met his wife, writer Ellen Abrams); he drew up white papers for a nonprofit in the financial district; he spent a year in the bowels of the old Boss Tweed courthouse, writing letters for New York City mayor Ed Koch. He helped a Vietnamese scholar write a book about Wittgenstein—a symbiotic relationship, Baker explains: "I knew nothing about Wittgenstein and he knew nothing about English grammar."

Then, in 1988, Baker's friend, radio and print journalist Jack Hitt, set him up with the job that changed his life. Hitt was going to Harper's, opening a research position with Harold Evans, who was writing what would become his bestselling book The American Century. The job would provide Baker with the stability and inspiration he needed to realize his novelistic ambitions. "Even though I was working much longer hours doing my own writing and writing for Harry," Baker says, "it was much more stimulating. I'd come back from the library raring to go." Three years into the 10-year job, he sold his first book, a baseball mystery called Sometimes You See It Coming.

All those hours in the library also opened up new literary possibilities. Combined with Ric Burns's documentary Coney Island, the facts Baker learned about American history inspired his first historical novel, Dreamland(1999), which opened his acclaimed City of Fire trilogy. So far, the series has earned him six "best book of the year" titles, two New York Times Notable Book citations and innumerable comparisons to E.L. Doctorow.

Set around seminal moments in New York City history—the Triangle Shirtwaist Fire of 1911 (Dreamland), the draft riots of 1863 (Paradise Alley), and WWII (Strivers Row)—the series reveals how hard it was for ethnic groups to gain political and social acceptance in the early 20th century. "One of the things I became more and more interested in as I was working on The American Century," Baker explains, "was how all these different groups pursued their own strategy toward democracy, toward inclusion."

Irish immigrants imported the idea of the well-connected village, he says, and infiltrated the city's infrastructure, taking jobs with firehouses and police stations. Jewish immigrants organized labor unions and demanded their constitutional rights. African-Americans rallied around Baptist churches and the Nation of Islam, building ethnic pride from religious conviction.

But if history can inspire fiction, Baker's work suggests that fiction can revise our understanding of history as well. One of the major characters in Strivers Row is Malcolm Little (a.k.a. Malcolm X), a man whom Baker believes fame has rendered an empty symbol. "Now all you see are the X-hats and the picture of him jabbing the finger forward, 'by any means necessary,' " he says. "But I doubt if one in 10 Americans could tell you what he really stood for, what the Nation of Islam was all about." And the real Malcolm X, he argues, is a much more complex figure than his popular autobiography—as told to Alex Haley—would suggest.

"The autobiography is a bid for power," Baker says, "It's a wonderful book but reading it, it struck me that there were all kinds of things in it that were unlikely or didn't add up." So he started comparing it with Bruce Perry's and Peter Goodman's scholarly biographies of the controversial civil rights leader, and in the process he developed a vision of Malcolm as a quintessentially American figure, one who was trapped between the ideas of black and white to a degree that he was not always willing to admit.

"The sad thing about his childhood is he's always being let in a little bit to this white world," Baker says. "You know, he's made president of his class, but he's not allowed to dance with the white girls."

Painting such scenes—the elation of a high school victory, the heartbreak of romantic frustration—with the techniques of fiction, Baker puts forth a more poignant portrait of the man, one that shows how Malcolm's personal experiences led to a belief in separatism while suggesting that, as a child, Malcolm's feelings about white people were quite ambivalent.

Strivers Row (the title refers to two blocks in Harlem, where the area's most prestigious residents lived)ends before Malcolm fully develops his political beliefs. But Baker, sitting in his Upper West Side apartment, where the walls are covered with baseball and World's Fair memorabilia, reveals his own opposition to his subject's militant program. "Black nationalism is certainly an understandable reaction to the centuries of oppression," he says, "but it's not a viable one. You can't just divide the world into a bunch of racial fiefdoms, nor should it be. If that worked, then the greatest place on Earth would be Yugoslavia."

For his next book, Baker will be returning to nonfiction; Pantheon will bring out his history of New York City baseball sometime in 2008. After that? He's got ideas for a historical novel about basketball and for another about political scandal in Manhattan and Coney Island. And then there's that novel he set aside after college, the one about his hometown, Rockport, Mass. He's been longing to get back to it and after 30 years, that might just work as historical fiction, too.