Portside

LOS ANGELES — Drawing on an American history of cruelty, from the conquest of the Indians to the slave trade to the internment of Japanese-Americans during World War II, activists in this city gathered on Thursday to voice outrage at what they see as the latest affront to American values by the Trump administration: splitting up migrant families at border crossings, and confining children in detention facilities.

“I think we are fighting for the heart and soul of America,” Yolanda Varela Gonzalez, a teacher and activist, told a crowd of several hundred protesters in MacArthur Park, before they marched to an immigrant detention center in downtown Los Angeles.

From the start, the Trump administration’s hard line on immigration has galvanized this city of immigrants, where nearly half the population is Latino, and where deportations and roundups of undocumented immigrants by government agents has spread fear and anger in immigrant neighborhoods. And the stories they have heard lately, and the images they have seen, of children being ripped from the arms of parents at the border have heightened a sense of outrage, a sense that they are experiencing an era of American history that will be looked back upon with shame.

“Taking kids from their parents is crossing a line,” said Gale Chernich, who joined the protest in Los Angeles.

Demonstrators in Los Angeles were joined by activists in dozens of other cities across the country on Thursday evening to protest the separation of migrant families under President Trump’s zero-tolerance crackdown on illegal immigration, enacted in May.

Organizers said more than 5,000 people had signed up to join the Families Belong Together rallies, aimed at halting one of the most widely debated new fronts in the Trump administration’s campaign to slow the flow of migrants across the southwest border from Mexico and Central America.

“Our goal is to shine a light on the family separation happening at the border and other points of entry into the United States and about the trauma that family separation inflicts on these children and their families and how wrong and, frankly un-American that is,” said Shannon McClain, a marketing specialist from New York who has helped coordinate the campaign.Ms. McClain said she began planning for the rallies after learning about the campaign on Twitter. Interest in the event grew exponentially, she said, as volunteers, many of them outraged mothers, jumped in to help.

In Suffolk County, N.Y., where Mr. Trump last year invoked a string of gang murders in the area to rail against undocumented immigrants, a crowd of dozens gathered in Huntington Village wearing yellow bracelets in solidarity with migrant families.

“Defense lawyers tell us that the parents being prosecuted for crossing the border are being made to wear yellow bracelets to denote their status,” said Eve Krief, a protest organizer.

Demonstrators sang and recited a poem. One speaker, Harold Fernandez, said he had come to the United States from Colombia, by way of the Bahamas, at 13. He said he was uncomfortable speaking to the crowd, but he spoke about a familiar issue.

“I’ve been separated from my family when I was a little child,” Dr. Fernandez said. His parents came to the country before he did.

Bob and Margaret Slifkin watched and listened, overwhelmed with emotion.

“This is not America,” Mr. Slifkin said. “This is not the country that I want to live in.”

At a rally in Austin, Tex., Nichole Miller, a local activist, said protesting the administration’s practices was crucial in her state, where immigration issues affect such a large share of residents.“We’re in the capital of Texas so there’s a lot more impact here,” Ms. Miller said. “It’s super important, I think, to start wherever we can all around the city but also get that message to our lawmakers, our governor and those who have an impact in D.C.”Micaela Eller, a leadership coach at I.B.M., said she had helped put together the rally in Austin after reading about the family-separation issue from stories posted on Twitter and Facebook.

“I read an account of a mother whose 4-year-old son had been taken from her and about her experience of being ‘processed’ with yellow wristbands with numbers on it to identify those families that were separated so they could be easily identified,” Ms. Eller said. “It was a gut-wrenching account, and as a mother, it broke my heart.”

Ms. Eller said she took to social media. Beginning with a couple of tweets to the actress Alyssa Milano, a prolific presence on social media with nearly 3.5 million followers who has been vocal about this issue, Ms. Eller was able to set up a rally in her city.

“I believe we are at a crossroads as a nation, and we have a choice to make,” Ms. Eller said, “and I wanted to make sure that my voice was among the loudest voices saying this is not O.K., and this is not who we are as a country.”

“The county that we live in is incredibly red so for that dynamic to exist and still have so much support I just think that it further proves that this issue goes beyond politics,” said Jennifer Kitchen, a field organizer who helped coordinate the event. She said she wanted her community’s interest to go beyond the demonstrations on Thursday.“There was a lot of conversation about what we need to do next and about how to keep showing up for immigrant families,” Ms. Kitchen said.

A similar protest unfolded Wednesday afternoon in Washington, where eight Democratic members of Congress marched alongside Cardinal Daniel DiNardo of Houston and other demonstrators outside the offices of United States Customs and Border Protection. Representative Joseph Crowley, Democrat of New York, suffered from heat exhaustion during the event but recovered shortly after.

In Los Angeles, many of the organizers were immigrants themselves, some of them undocumented — a fact they proclaimed loudly, calling themselves “undocumented and unafraid.” And many of the protesters were teachers from Los Angeles public schools, where they said they have seen firsthand how deportations have split up families, and how the children have suffered.

“They can’t focus on school or the future if we just take out the welcome mat,” said Elizabeth Kenoff, who teaches special education.

Organizers handed out yellow sheets of paper listing slogans, in English and Spanish, for the protest. “No hate! No fear! Immigrants are welcome here!” was one. “Say it loud! Say it clear! Immigrants are welcome here!” was another.

Carla Estrada, an organizer, said she is undocumented, and for years has been motivated by anger at how she has been treated — anger that came long before the Trump administration. Ms. Estrada, 27, said that when she graduated high school her counselor told her she would have no chance to go to college and that she should go back to Mexico.

“That propelled me into so much anger,” she said. She went to college, got her degree and now helps other immigrants.

Justino Mora, a software engineer, is also undocumented, and served as the master of ceremonies. He runs a nonprofit focusing on immigrant rights, and said what is going on in the country reminds him of a book he read about Manzanar, an internment camp in California where Japanese-Americans were sent during World War II.

“This is definitely a chapter in this country’s history, its xenophobic, racist history,” he said.