When Eileen Boussina moved from Los Angeles to San Francisco in 2003, she was 28, newly married, and knew hardly anyone in the Bay Area. She had joined a Los Angeles chapter of Hadassah, the Women’s Zionist Organization of Amer-ica, while in law school at UCLA, and when she called the organization to cancel her membership, she wound up transferring it to the San Francisco chapter.

Nine years later, Boussina can’t imagine her life here without the group. Especially for her, as the mother of a child with special needs, she says, the organization was a link to invaluable resources.

“It was this immediate sense of community, a network, a sisterhood,” said Boussina, who chairs the L’Atid (“The Future”) group for women ages 20 to 40 in the city’s Hadassah chapter. “Whatever I put into it, I got back twofold.”

Hadassah members around the Bay Area are reflecting on their own personal histories with the organization this week, as chapters in San Francisco, the East Bay and beyond celebrate a century of philanthropy, education, medical training and Israel advocacy work: Hadassah is turning 100.

Eileen Boussina

“Everything we do is based on our core values, whether it’s building hospitals, rescuing youth, establishing a college, planting forests, or sending children to Zionist youth camps and on Israel programs,” said Liz Alpert, Hadassah’s West Coast resource chair.

Hadassah was founded in New York City in 1912 by Henrietta Szold, a rabbi’s daughter who worked as the first female editor of the Jewish Publication Society. She was educated at the Jewish Theological Seminary of Amer-ica, which agreed to train her if she promised she would not pursue the rabbinate.

So she found another way to practice tikkun olam. After a visit to pre-state Israel, she founded Hadassah (the Hebrew version of “Esther”) with a biblical mission of Aruhat Bat Ami — “the healing of the daughter of my people.”

The all-volunteer organization’s first mission sent nurses to Palestine to provide pasteurized milk to infants and new mothers, and to eradicate eye disease. By 1918, Hadassah had sent 45 doctors, nurses and other medical workers to the area, serving anyone who needed help — regardless of religion or ethnicity.

That ethos is visible today in Hadassah’s work in Israel, where the organization (which now includes roughly 270,000 members, and is still overwhelmingly volunteer-run) founded the Hebrew University of Jerusalem’s Hadassah Medical School, the Henrietta Szold Hadassah-Hebrew University School of Nursing, and Hadassah College Jerusalem.

The Hadassah Medical Organization supports two other hospitals in Jerusalem, one of which opened a new $363 million tower this week. Hadassah doctors also work internationally; they were among the first on the ground in Haiti after the 2010 earthquake.

The commitment to treating people of all backgrounds is part of what has kept Rachel Sheinbein involved since 2001. That was when Sheinbein, 36, was among the first recruits into the Hadassah Leadership Academy, designed to attract a younger and more diverse group of women. The program included time in Israel, where Sheinbein visited Hadassah hospitals.

Sandy Sidorsky

“These hospitals are so incredible in terms of the care they provide, but they’re also really grassroots centers in terms of peace,” she said. “They’re treating people from all over the Middle East, and everyone’s treated by the same doctors, with a lot of humanity.”

The Diablo Valley Hadassah chapter is working with the Israel Center at the S.F.-based Jewish Community Federation to mark the centennial with a special celebration at this year’s Israel in the Gardens festival on June 10, said chapter president Sandy Sidorsky.

The anniversary is special to her chapter, she said, since some members are third- and fourth-generation Hadassah members.

“These are lifelong friendships,” said Sidorsky, 66, herself a member for 38 years.

In addition to these friendships, Sidorsky said, membership in Hadassah is “an important way to express my commitment to the state of Israel in a way that works with people.

“And the more I’ve been involved, the more I know about Hadassah, the more I realize how it impacts the rest of the world. Hadassah members learn what needs to be done, and then they turn around and they make the world a better place.”