Hoboken is surprisingly small, given its outsize reputation.

It’s only got 50,000 residents, and its nickname, Mile Square City, is roughly accurate. (“It actually covers an area of two square miles when including the under-water parts in the Hudson River,” Wikipedia helpfully tells us. It’s hard to understand why anyone would want to count the underwater parts.)

It’s a city with a storied history — Frank Sinatra, “On the Waterfront” and therefore Marlon Brando, gangsters, music, angst, longshoremen, gritty local color. Its lack of parking, which makes finding a space in Manhattan seem relatively as easy as finding one in, say, Montana, is legendary.

construction

Once the contract was signed in 1914, work on the building began.

For the last few decades, Hoboken’s been home to young people who work in Manhattan but don’t want or can’t afford to live there; it pulses with singles, who might make noises about staying but have tended to move once they’re married and certainly once they have kids.

Hoboken also has a more recent history of apparently being on the cusp, the verge, the very sharp tip of change, but somehow not quite making it.

That’s all changing now, though, for real. The city’s population has been growing. More and more people have been choosing to stay, and to bring their children up in the city.

There always have been Jews in Hoboken. United Synagogue of Hoboken is about to celebrate its building’s centennial; the congregation itself is almost a decade older, although it has changed shape considerably in that time. The synagogue, which is Conservative, is booming. Its preschool is bursting. People of all ages and of a range of Jewish backgrounds find themselves at home there. Its sense of community is palpable. It has a great deal to celebrate.

Rabbi Robert Scheinberg arrived at United Synagogue in 1997; he is believed to have set the tone for the synagogue’s revival, although he is too modest to claim that credit for himself. Instead, he talks about the distinct challenges and opportunities the shul’s densely packed urban environment provides.

“Hoboken is small, but it is routinely on the list of the five most densely populated areas in the United States,” he said. (That explains the parking situation.) Although it is less packed with people than its neighbors Union City and West New York, “it is way ahead of New York City, although probably not Manhattan separately,” he continued. And compared with Jersey City or Bayonne, which also has a synagogue, it is more urban in feeling. Members of United Synagogue “primarily live in apartments; some are in brownstones. Almost nobody is in a detached house.”

The shul is a medium-size community, with about 320 households. “The scale makes it hard to get lost,” Rabbi Scheinberg said. It’s probably still more transitory than most, but he sees that as an advantage: “There will always be a steady stream of new people. That’s useful and good for the vitality of the community.

“Both the stable population and the more transient people are at our core.”

One of the adjustments the community has made to that fact of its life is supremely practical. Because many people believe that to become a member is to commit to staying in the city, and because they often are not ready to make that commitment, at least not right away, “We never have had a building fund,” Rabbi Scheinberg said. “We don’t want people to feel that joining a synagogue has to be a multiyear proposition.”

That is the approach the shul takes to cultivating its leadership. “We want to identity people who are potential leaders within six months of their arrival, because we want them on the board by Year 2. They might be in the suburbs by Year 3.”

That is changing, however. “Now, though, the stable part of the community is growing, so that more of our synagogue leadership is from that group. But we try to make leadership opportunities available for people who are not sure that they will stay in the area.”

Another difference “that sets us apart is that the average age here is a lot younger than in most other places,” Rabbi Scheinberg said. “And we are also seeing a lot of empty nesters, young retirees. That is a growing segment of the community.” Overall, he estimated, the average age of his congregants is probably somewhere in the early 40s. “Younger than I am — I’m in my mid-40s,” he said, a bit ruefully.

There are not many synagogues in the area. Chabad opened one recently, and there is a Reform shul in Jersey City that attracts a few Hoboken residents, but for most of United Synagogue’s long history it’s been the only game in town.

United Synagogue of Hoboken is “an informal place,” Rabbi Scheinberg continued. “It’s one of my goals that no matter what someone wears — a suit and a tie, or anything else — that they should feel comfortable. They should feel that they’re not being judged by what they’re wearing.

“We strive to be informal and inclusive.”

Another aspect of the shul’s informality is the rabbi’s approach to sermon-giving. “Instead of a sermon, I lead a discussion of the parasha,” the Torah reading, he said.

Other demographic distinctions are the number of couples “where one partner is Jewish and the other is not, and also the number of people who are involved in the conversion process, or who have converted. This correlates with the ethnic diversity in the community.

“Some of these things may have made us more distinctive 20 years ago than it does today,” he conceded. “There is not a single role in Conservative life that has not been played by someone who converted. We are the location for the Introduction to Judaism course run by the Rabbinical Assembly of New Jersey” — the association for local Conservative rabbis. “That’s because we always have so many people looking to convert.”

Lauren Sapira, an active member of the shul who works in publishing, tells a story that echoes some of the themes Rabbi Scheinberg brought up. “I have been here in Hoboken for 21 years,” she said. “When I first moved here after college, I assumed that it would be for just a few years.

“I grew up in Livingston, and I always assumed that I would move to the suburbs.

“I definitely can say that the thing that has kept me in Hoboken is the synagogue and the community,” she continued. “It is a unique community. People are here because they want to be here, not because they feel that they should be here.

“I am amazed every year at Neila” — the emotionally and spiritually draining and exhilarating service at the end of Yom Kippur — “how the place is just packed. After we have finished, after the last shofar blast, nobody leaves.

“Everybody stays for Havdalah. Nobody has eaten for 25 hours, and everybody stays so we can all do Havdalah together. It’s that kind of place.”

Ms. Sapira is a product of the Conservative movement’s United Synagogue Youth, and then of Hillel at Cornell University, so once she graduated from college she knew that if she was to feel at home somewhere, she had to be part of its Jewish community. When she got to Hoboken, she found one that was small and intimate, but also struggling.

“When I first started going to the synagogue, there wasn’t much in terms of young people,” she said. “That was a little discouraging at first. I was asked if I would help run singles events, even though I didn’t really like the idea, because the whole idea of singles events is to meet people so you never have to go there again.”

Because she knew that people in their 20s often do not want to affiliate with a synagogue but she also knew that she wanted a peer group for herself, Ms. Sapira and some friends put together Jewish events that met in other places. “The first event was a Purim party in a bar in town,” she said. “We purposely kept it out of the synagogue for a number of years. We liked going to Friday night services, so people started coming along, and we built up a whole Friday night community, and then Saturday morning at times.”

At first, the group would go to services and then to a restaurant for dinner; soon they graduated to pot-luck dinners, and then to full-on Shabbat dinners in each other’s homes. “At that point, people wanted to be part of a community,” she said.

The shul is named United Synagogue of Hoboken for the most straightforward of reasons. It was formed by the merger of two earlier communities, the Star of Israel, which had been Orthodox, and the Hoboken Jewish Center, which was Conservative. After the merger, the community used both buildings, the Jewish Center’s brownstone and the Star of Israel’s larger structure. In the 1970s, when the community reached its nadir, “they almost sold the Star of Israel building,” Ms. Sapira said. “They could have gotten good dollars for it. But they decided not to.

“And then, in the late ’90s, we made a momentous decision — that we needed to consolidate everything, that we were better off selling the brownstone, consolidating, expanding, and putting in a preschool.

“I was 29, and I on the board. I said ‘Why build a preschool? No one will stay here. No one will use it.’ What did I know? We built it — and people stayed.

“That was in 1997 or 98. The preschool started in 2000. When I had my son, in 2003, all of a sudden we thought ‘We don’t have to move!’

“When they decided to build, I thought they were crazy, and then I became one of the first to say that we should stay.” Now the Sapiras have two children. Both are graduates of the nursery school and now in the shul’s religious school.

It is not only United Synagogue of Hoboken that has changed over the last two decades, Ms. Sapira said. Hoboken is different too. “When I moved to town in 1994, it was all about the bars. The bars are still here, but now they are allowed to serve food, and look at how many high chairs there are!

“Wolfgang Puck,” the famous restaurateur, “opened a restaurant in Hoboken in 2004, called Wolfgang Puck Express,” Ms. Sapira said. “It’s closed now. But we went there when it was open, and asked for a high chair, and he said ‘We keep running out of them. Nobody told me we’d need so many high chairs.’

“While he was waiting for the building the restaurant was in to go up, he did research on the neighborhood. It took two years, and by the time the community had changed so much.

“Now there are kids’ activities all over the place. Theater, dance, sports — all of sudden everything’s everywhere, and you can’t possibly keep up.”

United Synagogue of Hoboken is kid-friendly, she said. Every Shabbat, children are invited to follow the Torah in the procession as it is taken out of the ark, and “when they get back, they go up on the bimah, kiss the Torah, and then everyone sings Hinei Ma Tov” — how good and pleasant it is for brothers and sisters to live together. Later, they come back on the bimah. “The rabbi thanks every single one of them by name,” she said. “He knows every single one of them by name. That makes them feel like it’s their home.”

There are anywhere from 30 to 60 children any given week, she added.

When synagogue leaders decided to plan the upcoming celebration, they decided that the community and the building it calls home could not be teased apart, so they focused on the building itself.

Alexander Gorlin, a Manhattan architect who specializes in synagogues and other places of worship, oversaw a major renovation in 2000.

“We restored the interior to its original glory,” he said. “We decided to create a color palette that would be in keeping with the original date of the building. It is a series of sky blues and creams, based on 19th century Victorian palettes.”

The building, which sits very close to the street, in touch with the outside world, is compact and vertical. It is “clearly a town synagogue,” Mr. Gorlin said. “It is appropriate to the size of Hoboken, kind of a complementary province to the city just across the river. It is definitely an urban building. Its charm comes in part from the exotic onion domes, the Byzantine style that became appropriate for Jewish congregations in the 19th century.

“It has an intimacy that is charming, and almost recalls the Jewish experience in Europe before the war.

“It is to be cherished as a neighborhood landmark; even apart from its function as a synagogue it gives character and identity to the immediate neighborhood.”

Susan Klein has been a member of United Synagogue of Hoboken since 1987. She is also an artist. Joining those two identities, she has restored or created the building’s old windows, removing the bars that held them together, using stronger, more modern lead — and also her own vision — producing original, compelling stained-glass artwork.

She is providing the direction; other synagogue members work with her, experiencing the hands-on pleasure of creation. All are volunteers.

Some of the windows in the sanctuary had been plain glass. Ms. Klein is replacing them with artwork showing the seven days of creation. She incorporated found objects into the glass, making the windows a marvel of texture as well as shape and light, rendering them surprising as well as beautiful.

She had never used this technique before, but she had the materials and the idea demanded some experimentation. “I had the bottom of an Israeli bowl that I had bought when I was a kid, and broken years ago,” she said. She is using that as the center of a nebula in the window showing the first day of creation. “There are swirly blobs of glass, a swirly bubbly thing.”

On the fifth day, the Bible tells us, God’s creations include fish. Ms. Klein included shells and a “really gorgeous mother of pearl” piece that “sticks far out” of the frame for that day’s window.

Ms. Klein has taken the opportunity of making the windows to comb through her store of interesting or beautiful objects, and to go on shopping expeditions to find more. Her finds often end up in the sanctuary.

Next weekend, United Synagogue of Hoboken is going to celebrate the building’s centennial by acknowledging its three identities — as a beit tefilah, a house of prayer; a beit midrash, a house of study, and as a beit am, the people’s house and the community’s center. It also will celebrate the community’s sturdy, stubborn independence and resolve, the Hoboken-like virtues that are likely to see it well into its second century.