Barbara Blaine, president of the Survivors Network of Those Abused by Priests (SNAP), holds childhood photographs of adults who say they were sexually abused. (Matt Rourke/AP)

In the summer of 1969, 13-year-old Barbara Blaine was part of the Deaconettes, a group of junior-high girls who cleaned up after Mass at their parish in Toledo. They had been invited to dine with Father Chet Warren as a reward.

After the meal, Ms. Blaine recalled, she found herself alone with Warren, who told her she was special, holier than the other girls, and then molested her. He wanted her to go to confession right away and tell no one else because they wouldn’t understand, and would not believe her anyway, she said.

The alleged abuse continued until Ms. Blaine’s senior year in high school and remained a secret until 1985, when a newspaper ­story on sexual predators in the Catholic Church led Ms. Blaine to tell her parents and seek out other survivors.

“I had this basic feeling of being dirty and bad that I carried around for years,” she told The Washington Post in 2002. “I carry with me the sense that I’m a bad person — I think that’s still there.”

Ms. Blaine, who died Sept. 24 at 61, founded the Survivors Network of Those Abused by Priests in 1988. The group — known as SNAP — held its first meetings in a Chicago homeless shelter and hotel conference room. It now organizes advocacy efforts and survivors’ meetings in 60 cities around the world, working with more than 20,000 members.

Ms. Blaine, with SNAP director David Clohessy at left, at a news conference in Dallas in 2002. (L.M. Otero/AP)

The organization has been credited with successfully lobbying for more “survivor-friendly” laws, including ones that would extend the statute of limitations, and recently expanded its focus to include advocacy on behalf of sexual abuse victims at schools and in the Boy Scouts.

“Few people have done more to protect kids and help victims than Barbara Blaine,” Barbara Dorris, managing director of SNAP, said in a statement. “Her relentless advocacy enabled millions to eventually accept a long unbelievable reality: that tens of thousands of priests raped and fondled hundreds of thousands of kids while bishops hid these heinous crimes.”

Ms. Blaine, as president of an organization that for many years had no budget and no staff, scoured news stories and met with legal advocates to develop a national network of sex-abuse victims. The group held volunteer-run meetings in cities across the country, offering a forum for individuals who had frequently never discussed what had happened to them as children.

Along with groups such as Victims of Clergy Abuse Linkup, SNAP spent years trying to draw public attention to recurrent ­cases of abuse and lobbied church officials to change policies that protected alleged abusers. The group was a persistent, and persistently skeptical, presence at gatherings of the National Conference of Catholic Bishops.

SNAP’s profile was elevated after the Boston Globe published its 2002 investigative series on clergy sex abuse and a “culture of silence” in the Catholic Church.

The series, which included the revelation that one Boston priest had molested more than 130 children while the church moved him from parish to parish, was awarded the Pulitzer Prize in public service. (The reporting effort was chronicled in the Oscar-winning movie “Spotlight” in 2015.)

Ms. Blaine, working a day job as an attorney for abused children in Chicago’s Cook County, was soon inundated with phone calls from victims around the country. With SNAP’s national director, David Clohessy, she opened the organization’s first national office in Chicago in 2003 and began taking a salary to work for SNAP full time. (The organization’s headquarters moved to St. Louis in 2016.)

Mark Serrano, a former altar boy who was sexually abused by a priest in New Jersey, told the Chicago Tribune in 2002 that Ms. Blaine was part of a group of “true warriors for justice.”

“They were out there — for no personal gain — when no one else was,” he said. “Without them, there would be even more suffering.”

Barbara Ann Blaine was born in Toledo on July 6, 1956. Her father led the local parish council, and her mother was a member of the altar and rosary society.

Abuse by Warren, she said, caused her grades to suffer in high school and led her to distance herself from her family as well as from men. “Even after the abuse ended,” she told the Toledo City Paper in 2004, “I didn’t want anything to do with any kind of intimacy.”

When Ms. Blaine first told another priest about Warren, she was told that Jesus loved her and would forgive her. Later, when she met with parish leaders in 1985, she was told that she had probably “misinterpreted” Warren’s actions.

Warren continued preaching until 1992, shortly before Ms. Blaine appeared on “The Oprah Winfrey Show” to discuss his abuses. According to the Associated Press, he was eventually banned from the ministry.

Because of the statute of limitations in Ohio, Ms. Blaine was too late to push for criminal charges, but she reportedly received $80,000 in an out-of-court settlement.

She studied theology and social work at Saint Louis University, a Jesuit school, and received a master’s degree in social work from Washington University in St. Louis. She also received a master’s in divinity from Catholic Theological Union and a law degree from DePaul University, both in Chicago.

According to a statement from her family, she died while on vacation in St. George, Utah, days after suffering a spontaneous coronary artery dissection — a torn blood vessel in the heart. Survivors include her husband of 15 years, Howard Rubin of Chicago; two stepsons, Brett and Joshua; seven siblings; and two grandsons.

Ms. Blaine resigned from SNAP on Feb. 3 to start the Accountability Project, an effort to stop clergy sex crimes around the world.

Her departure occurred shortly after the resignation of Clohessy and the filing of a Jan. 17 lawsuit against the organization, in which a former development director accused SNAP of taking kickbacks from victims’ attorneys and profiting from settlements. The bulk of the organization’s donations, the suit claimed, came from donations from lawyers whose clients were referred by SNAP.

The organization denied that it was engaged in a kickback scheme and said Ms. Blaine and Clohessy’s departures were planned well before the suit was filed.

In interviews, Ms. Blaine said she never expected her organization to last more than a year. Healing from sexual abuse, she assumed, would simply be a matter of a few monthly meetings.

“Now I understand it’s a lifelong process,” she told the Tribune in 2012. “I thought it was something you heal from like a broken leg. I never realized it would take so long.”