Mention Harlem, and icons of African-American history spring to mind -- the storied Cotton Club, home to Josephine Baker and Duke Ellington, or Marcus Garvey's failed Black Nationalist movement of the 1920s.

But in Sharifa Rhodes-Pitts' "Harlem Is Nowhere: A Journey to the Mecca of Black America," the legend of the neighborhood collides with its present-day reality of poverty, political disenfranchisement and power brokers' relentless attempts at gentrification.

The title, lifted from a Ralph Ellison essay about "how little has changed in the ghetto," also echoes the book's general conclusion: Save for its near-mythical past, Harlem's struggle to cope with its faded history, hardscrabble present and fight to define its future is pretty common in black urban neighborhoods these days.

Part diary, part history lesson, Rhodes-Pitts' book chronicles her years-long pilgrimage from Texas to the storied place once known as Black Mecca. Enticed by Harlem Renaissance writers such as poet Langston Hughes, Rhodes-Pitts launches into a project to comprehend a complex, contradictory neighborhood.

"I did not understand how this place had existed as haven and ghetto," she writes, describing the conflicting knowledge she learned as a black Southern schoolgirl curious about Harlem. "It seemed, to my teenaged mind, a great paradox. It also revealed something about the history I had learned -- a flattened version of events where a place is allowed to be only one thing or the other."

The story of Harlem, she finds, mirrors most urban black neighborhoods. During the Great Migration, African-Americans from former slave states came to segregated Northern cities, creating thriving, self-contained communities with bustling arts movements -- think Chicago's South Side, famous for the blues, or Detroit's Black Bottom, among the inspirations for the Motown sound.

Desegregation, however, spurred exodus and collapse; hard times followed for residents who couldn't afford to leave, or didn't want to. Land-hungry developers, spurred on by city leaders eager to erase urban blight, eyed those neighborhoods for luxury condos, displacing residents in the process. Harlem, black America's crown jewel for decades, couldn't escape that fate.

In Harlem, Rhodes-Pitts struggles to find quality affordable housing and middle-class shopping, but also encounters welcoming residents who exemplify Harlem's early population of blacks fleeing Dixie. She also finds aging black radicals, street people and the Caribbean and West African immigrants who are the changing face of the neighborhood.

Working in the Schomburg Center for Research in Black Culture, Rhodes-Pitts unearths gems from Harlem's rich history, including the White Rose Society, a 1920s benevolent organization for young black girls migrating to the city; Raven Chanticleer, a sharecropper's son who became a legendary dancer and founder of a black history wax museum, and L.S. Alexander Gumby, a turn-of-the-century intellectual who catalogued black history in a series of scrapbooks.

An elegant, scholarly writer, Rhodes-Pitts is at times maddeningly vague about the scope of her project, distracting from the depth and detail of her research. It also was hard to determine if -- and when -- she crossed the line from self-described observer and journalist to activist, particularly during anti-gentrification meetings.

Still, given the new ground she covers on an old subject, "Harlem Is Nowhere" is worth the trip.

Joseph Williams, a former editor at the Star Tribune, is an editor at Politico in Washington, D.C.