It’s a chilly autumn morning in Harlem, and East 112th Street between Lexington and Third is virtually deserted. Jeffrey Gurock, the longtime Yeshiva University history professor and maven on all things Jewish in Harlem — “When you Google ‘Harlem Jews,’ my name comes up” — is driving his Saab around the neighborhood, pointing to buildings where thousands of Jews prayed decades ago and places where they studied. Gurock is giving a single visitor the type of group tour he’s been leading by foot for 35 years.

He pulls up in the middle of the block, in front of the Christ Apostolic Church of New York, its maroon brick-façade entrance and maroon staircase locked by a black metal gate, and begins telling stories. The story of the church that once was a synagogue. The story of the neighborhood that once was a center of Jewish life (175,000 Jews a century ago) and is now once again becoming a home for Jews. And his own stories — as a chronicler of the past and present of Jewish Harlem, and of the time he prayed in the building across the sidewalk.

He starts with history.

“This was the first home of Ansche Chesed,” a landmark New York synagogue that eventually moved to larger quarters in Harlem, and then to its current home on the Upper West Side, Gurock says.

Then he turns personal.

In 1974, already interested in the Jewish history of Harlem, having written a doctoral thesis that grew into “When Harlem Was Jewish, 1870-1930” (Columbia University Press, 1979), he heard that a synagogue was still functioning in Harlem.

He spent a Shabbat with friends on the Upper West Side, and, as a Modern Orthodox Jew, walked the half hour north to East 112th, not knowing what he would find.

He found Tikvath Israel. The doors were open. In the pews were nine “old, old, old” men. The 10th man in the traditional shul, he made the minyan. “I did the Haftarah” — as an honored guest, he was asked to chant that morning’s prophetical reading. Then he walked back to the Upper West Side. “There was no kiddush.”

Gurock tried calling the synagogue a few months later. The number was disconnected. The last shul of Harlem — he doesn’t count one longstanding Jewish house of worship that is closer to Columbia University and technically isn’t in Harlem — was gone.

Another part of Jewish Harlem, whose Jewish community was the third biggest by World War I, had disappeared. By the 1930s, prodded by black migration from the South and lured by tax breaks in the outer boroughs, most of Harlem’s Jews had moved out.

Yes, Harlem was Jewish, with an emphasis on the past tense.

Until Jews started moving back by the early aughts. That’s a subject that Gurock, the author or editor of 19 books, documents in his latest one, “The Jews of Harlem: The Rise, Decline, and Revival of a Jewish Community” (New York University Press).

In 277 pages, Gurock discusses Jewish politics, Jewish characters admirable and not so admirable, the dynamics of black-Jewish relations, the reasons behind the growth and diminution and renaissance of Harlem Jewry
and “the cultural imprint” of Harlem’s Jews.

“This is in no way a second edition” or an updated version of “When Harlem Was Jewish,” he says. “It’s a very different book.” More available research sources. More perspective on the neighborhood’s history. “Much less numbers crunching – this work is far more accessible than the first.” This book is more personal, too — Gurock mentions his late father, who grew up in a Harlem tenement, and the Jewish couple who in 2008 alerted him to Harlem’s re-emergence as a destination for Jews.

“There’s 85 years of history that was not in the first book,” he says.

Why was a second book on one neighborhood needed?

Forty years after his first book on Manhattan’s storied neighborhood, Jeffrey Gurock has returned to the subject — and to Harlem. Above, the first home of Ansche Chesed, now the Christ Apostolic Church on East 112th St. Steve Lipman/JW

Harlem is now undergoing a neighborhood-wide renaissance nearly a century after the original Harlem Renaissance that established the area as a center of creative black cultural life; where white residents have outnumbered black residents for the last decade, “is a hot topic generally in American life,” Gurock says. “The book’s doing very well. Everyone’s interested in Harlem.”

Members of the Jewish community express two reactions when they hear of Gurock’s academic interest. “To this day,” he says, “People say, ‘I never knew there were Jews in Harlem.’” Or they say, “My bubbe and zeide lived in Harlem.”

Gurock had left Harlem some four decades ago, but Harlem never left him.

Like him, other Jews find the changes in Harlem fascinating, he says.

“Harlem is returning,” but it’s not his grandfather’s Harlem. The story “is worth retelling.”

Gurock returns to the tour. There, he points to a one-time synagogue, its Ten Commandments still visible up high. There, to another former shul. There, to a building where a Talmud Torah or some other Jewish institution was located. When Gurock closes his eyes, he says, he can imagine “people dressed to the nines walking along the street,” and Jewish kids playing in the schoolyards.

He takes Jewish groups, mostly from synagogues, around the neighborhood several times a year. “They don’t get a tour guide — they get a historian.”

Soon, Gurock runs out of once-Jewish buildings to point to. “These are the only buildings left.”

Some of the smaller shuls folded, he says. Many were sold to churches. Others made way for housing developments. The larger ones relocated largely to the Upper West Side.

While the Upper West Side remains the address for much of the city’s Jewish life, many Jews, especially young couples who could not afford to live there, started looking a few miles north a few decades ago. Today, gentrified Harlem is home to a Chabad center, a Hebrew-language charter school and a newly opened JCC, a branch of the JCC Manhattan on the Upper West Side. An estimated 6,000-7,000 Jews live there. “There’s an eruv here, too,” Gurock points out.

His latest book is another sign of Jewish Harlem’s vibrancy. It’s “a teaching moment regarding how a city revitalizes itself,” he writes in the book’s last chapter. “What started among and to Jews in the streets and institutions uptown did not stay in the neighborhood and had crucial implications for Jewish life well beyond the metropolis.”

“It would make sense that younger Jews in search of affordable housing would find their way back – Harlem had been rising for a long time before the Jews arrived,” says Steven M. Cohen, research professor of Jewish social policy at Hebrew Union College and a consultant to the 2013 Pew study of American Jews. “These things are somewhat predictable.”

Will Jewish Harlem keep growing?

“It’s just the beginning of return,” Gurock answers.

The morning’s tour is over. One more question: Will Gurock write another book about Jewish Harlem in 40 years?

“I hope to be around,” Gurock, 67, says. Harlem’s Jewish revival “is only starting,” he says. “It’s a story to be watched.” Someone will have to write that history. “I hope to be that Jewish historian.”

Jeffrey Gurock will discuss his research about the Jews of Harlem on Wednesday, Dec. 14, 6:30 p.m. at the Mid-Manhattan Library, 455 Fifth Avenue, (212) 340-0837; and Sunday, Dec. 18, 10 a.m., at the Hebrew Institute of Riverdale, 3700 Henry Hudson Parkway, (718) 796-4730.

steve@jewishweek.org