CROSSING LINES: Histories of Jews and Gentiles in Three Communities, by Judith S. Goldstein. Morrow, 320 pages, $23.

Between 1891 and 1910 more than 1 million Jews took flight from the persecution and grinding poverty of Russia to seek freedom and opportunity in America. To their dismay they found acculturation to be an intimidating process, grounded in a clash of religious and cultural differences whose dichotomies spawned anti-Semitism.

Upon arrival in the United States, most of these Russian Jews settled in the teeming ghettos in New York City and Boston, but the bolder, more adventurous of their numbers spread out over the country. In one such diaspora, some 2,000 emigrated to Maine. How they fared in three of this state’s communities — Bangor, Bar Harbor and Calais — is the theme of Goldstein’s illuminating and socially significant “Crossing Lines.”

The author, a resident of Mount Desert’s Bar Harbor, received her master’s degree and doctorate in history from Columbia University. She deftly demonstrates her skill in this discipline by seamlessly interweaving the long ordeal of the Jews in finding their niche in a gentile society with the detailed histories of their adoptive communities, from the turn of century to the present.

First she focuses on the surge of wealth generated in Bangor in the Gilded Age by the development of its lumbering industry and the subsequent dwindling of its power with the influx of land speculators, the railroads and paper companies.

Goldstein then turns to Mount Desert, a quiet cluster of fishing and farming hamlets loomed over by the majesty of mountains and fragrant with the salty breath of the sea. Doomed to change, the author relates: “By the mid-1870s, Mount Desert had been discovered. … Developers — the native-born, along with those from Bangor (less than 50 miles away), south to Philadelphia — bought properties, built houses and opened up roads.” The beauteous Bar Harbor became the summer playground of the Social Register rich, as did Northeast Harbor and Seal Harbor.

The book’s third venue, Calais, lies in wilderness Washington County, 98 miles north of Bangor. A tranquil border city of about 4,000, it shares the St. Croix River with St. Stephen, its Canadian sister city.

Arriving in Maine, many Jews became peddlers. By scrimping and saving they moved up the economic ladder to the status of merchants. Peddling in the coastal and rural regions whose inhabitants were dominantly Anglo-Saxon and Protestant was difficult, often demeaning, but the Jews accepted it as an unavoidable rite of passage. They had three motivating goals: to help relatives emigrate from Russia to America; to obtain for their children the finest education America had to offer; and to preserve the integrity of their own Jewish religion.

Faithful to their vision, in 1888 the Bangor Russian Jews organized “the nucleus of Beth Israel, Maine’s first permanent congregation.” Nine years later the cornerstone for the permanent building was laid in a ceremony during which, according to the newspaper account in the Bangor Daily Commercial, prayers were led by Rabbi Goldenkop “in the Hindoo language.” It was an egregious blunder, expressive of the gap between the Jews and Bangor’s Protestant ruling class.

Winds of change were blowing. By the 1930s Russian Jewish names were appearing on Bangor’s civic roster, names such as Myer Minsky, A.B. Friedman, Morris Rosen, and Abraham Rudman, the first Jew appointed to Maine’s Supreme Court; along with Helen Golden, Lena Ginsburg, and Catherine Cutler, wife of Dr. Lawrence Cutler, son of a Bangor peddler, who achieved another first for his race when he was appointed to serve on the staff of the city’s Eastern Maine General Hospital. When invited to fill its newly created post of chief of medicine, he accepted with the priviso that henceforth the board of trustees cease to practice discrimination in hiring doctors.

For a long time the only Jews to gain entry into the exclusive inner circles of Bar Harbor were those who had married gentiles, as for instance Walter Damrosch, celebrated conductor, and husband of the daughter of Maine’s Sen. James G. Blaine who was later to become U.S. secretary of state. Joseph Pulitzer, newspaper magnate, was another. His wife, Kate Davis, was a gentile society woman “who had learned to her dismay, only after their wedding, that her husband was Jewish.” On the other hand, banking titan Jacob H. Schiff and diplomat Henry Morgenthau Sr. made no bones about their Jewishness and were active in the anti-Semitism movement.

“In the confrontation in Maine of … the Protestant hosts and Jewish immigrants — it may come as no surprise that Charles W. Eliot (nationally renowned educator), John D. Rockefeller Jr. (the philanthropist), Jacob H. Schiff and Henry Morgenthau Sr. emerge as dominant figures,” writes Goldstein.

Without a doubt, the saltiest of all the Jews in this immigrant admixture was Sarah Unobskey, feisty business wizard who left her home in Snovsk, Russia, in 1911 to join her husband, Joseph. In Calais they cofounded the famed minidepartment store Unobskey’s, which ultimately, under Sarah’s direction, became the attraction for thousands of shoppers from as far away as Canada’s Fredericton and Saint John. Her choice of Calais as the site of their store was strongly influenced by the city’s friendly tolerance.

Widowed at an early age, the indomitable Sarah, mother of three sons, the eldest of whom was Arthur, heir apparent, eventually purchased the entire block in which her store was situated. Every building on the block had a “U” carved into it, including the State Theatre, “latest in fireproof construction, attractive fixtures and a fine large stage.” Despite her reputation as a hard-nosed businesswoman, Sarah showed her gratitude to Calais during the Depression of the 1930s by expanding rather than retrenching her business interests.

She was squat, heavy and dogmatic, the boundaries of her world “defined by rigid moral judgments,” says Goldstein. Yet she was lighted from within by a genius for business that illuminated her entire life, proving to other women that if Sarah Unobskey could do it, they could too.

“Crossing Lines,” couched in chiseled prose, sends off sparks of inspiration Venus-bright with historical fact. More than a century ago Voltaire wrote: “I know how much history can teach us. I know how necessary it is; but truly it needs much help if one is to draw from it any rules of conduct.” Goldstein’s book makes that quantum leap into the human principles of, and necessity for, tolerance and true freedom from bigotry.

Bea Goodrich’s reviews are a regular feature in the monthly Books in Review section. Goodrich also writes a review column, and is the author of the award-winning nature story series, “Happy Hollow Stories by Judge Tortoise.”