People attend a Washington National Cathedral vigil against gun violence Thursday. The crowd included several people from Newtown, Conn., the site of a mass shooting at an elementary school a year ago. (Bill O'Leary/The Washington Post)

Newtown and Aurora in 2012. The Empire State Building in 1997. South Capitol Street in 2010. Loved ones of victims of prominent and less-known shootings lighted candles, prayed, sang and called for legislative action Thursday during a vigil at Washington National Cathedral aimed at stemming gun violence.

Many of the 800 people inside the cavernous Northwest cathedral were gun-control advocates, including rabbis, imams, priests, teenagers who lost friends, and parents who lost children. The crowd seated in rows of wooden chairs included two busloads from Newtown, Conn., where one year ago Saturday a massacre of 26 children and staff took place at Sandy Hook Elementary School.

“Please let our profound grief over gun violence continue to encourage us, to engage [us] in reckless and wanton acts of compassion and care,” the Rev. Kenneth Samuel of the Victory for the World Church in Stone Mountain, Ga.

With a hymn from singer Carole King and a piano-violin pair playing John Lennon’s “Imagine” — Lennon was shot dead 33 years ago this week — much of the National Vigil for Victims of Gun Violence was apolitical. But some speakers urged Congress to take a stand.

D.C. Del. Eleanor Holmes Norton (D) compared the push for greater gun control and mental health treatment access to legal crusades for racial and gender rights. She said she had just come from the memorial service for Nelson Mandela, South Africa’s former president.

“I am speaking for these few minutes more about persistence than about any other human characteristic,” she said. In South Africa, “I was reminded during that service just how much justice requires determination; even through our own history, do not forget that only those who persevered prevailed on any issue in the Congress. Do not be discouraged.”

With so many representatives from Newtown, the service was a rare public event related to the anniversary, as many families of victims had asked for privacy this week.

The event was organized by the Newtown Foundation, a nonprofit organization focused on gun control, and the cathedral, a prominent Episcopal church whose leaders in the past year have singled out issues such as racism and gun control for advocacy efforts.

The vigil began with three minutes of bells quietly tolling, each minute for 10,000 people killed by guns in the past year in the United States.

“The gun lobby is no match for the cross lobby. . . . As Christians, we follow one who died at the hands of human violence,” said the Very Rev. Gary Hall, dean of the cathedral. “We call our elected leaders to find the moral courage and the political will to lead us all into a new, safer era in American history. . . . Make us instruments of your peace, and strengthen our hearts and hands and minds not only to care for the victims and survivors of gun violence but also to bring about the change that will end the violence caused by guns in the hands of the criminal, the sick, and the cruel.”

People who came from out of town for the vigil participated in a day of service Thursday and did some quiet lobbying with members of Congress. Lawmakers this year did not pass background checks and other gun laws, and groups are shifting their focus to the states.

Among those who spoke at the vigil was a father who lost his daughter, a teacher in Newtown, and a man whose brother was shot in the head on the Empire State Building observatory platform 16 years ago.

Several clergy members came from Newtown, including the Rev. Matthew Crebbin of Newtown Congregational Church.

“Even though the shadows of despair press upon so many, let us pray for grace to appear in the dark of the night of fear and apathy,” he said. “A light shines in the darkness and the darkness does not overcome it. Let us become light for one another, for all the world to see.”

Sayyid Syeed, director of the Islamic Society of North America, said Americans should compare gun control to the issues of chemical and nuclear weapons.

“This nation provided leadership to the world. . . . We ensured to the rest of the world that these weapons wouldn’t fall into the hands of people who would use them to destroy,” he said.

Nardyne Jefferies, whose 16-year-old daughter was killed in a 2010 drive-by shooting on South Capitol Street, said she was robbed by the loss of her only child.

“We had a lot of things planned and one bullet blew her head off and changed my life. . . . I was robbed of future generations,” she said. “I’m thankful people are here, and unfortunately many more will come after us.”