WASHINGTON — About 750 Families Belong Together rallies drew hundreds of thousands of protesters into the streets Saturday in every state of the country — from big cities such as Boston, New York, and Chicago to tiny ones such as Antler, N.D., population 28.
The message to President Trump: End the ‘‘zero tolerance’’ immigration policy, which has split children from their parents and detained families crossing the Mexican border.
Protesters wore white, shook their fists in the air, and carried signs reading: ‘‘No more children in cages’’ and ‘‘What’s next? Concentration camps?’’ Some in Denver donned foil blankets like the ones given to children in Texas detention centers.
The demonstrators included immigrants, activists, and parents moved by accounts of children being separated from their families at the US-Mexico border. People turned out not just in immigrant-friendly cities like New York and Los Angeles, but in conservative communities in Appalachia and Wyoming.
In Trump’s hometown of New York City, an estimated 30,000 marchers poured across the Brooklyn Bridge in sweltering 90-degree heat, some carrying their children on their shoulders, chanting, ‘‘Shame!’’ Drivers honked their horns in support.
In Boston, thousands gathered on City Hall Plaza to listen to speeches from Senators Elizabeth Warren and Edward J. Markey, and Representative Joseph P. Kennedy III before marching a short distance to Boston Common.
“Children belong with their parents,” Kennedy said. “We see our humanity in the eyes of those children locked in those cages and we will not accept it.
Trump has backed away from the family separation policy amid wide criticism, including from members of his own party, but those marching Saturday demanded that the government quickly reunite the families that have already been divided.
Protesters gathered in front of a Border Patrol station in McAllen, Texas, near a detention center where migrant children were being held in chain-link detention areas, and on a street corner near Trump’s golf resort at Bedminster, N.J., where the president is spending the weekend.
‘‘Do you know where our children are?’’ one protester’s sign there asked. Another offered: ‘‘Even the Trump family belongs together.’’
At the Los Angeles rally, Representative Maxine Waters called for Trump’s impeachment, while Senator Kamala Harris said migrant children taken from their parents will suffer lifelong trauma.
The events were mostly peaceful, but a few arrests were reported in Dallas and Columbus, Ohio.
In the nation’s capital, tens of thousands of people gathered in Lafayette Park across from the White House in a demonstration that went on for hours in searing heat.
Lin-Manuel Miranda, the creator of the musical ‘‘Hamilton,’’ sang a lullaby dedicated to parents who are unable to sing to their children. Singer-songwriter Alicia Keys brought her 7-year-old son, and read a letter written by a woman whose child had been taken away from her at the border.
With temperatures hovering in the 90s in downtown Washington, organizers made repeated calls to the crowd to drink water and use sunscreen. Firefighters at one point misted the crowd to help people cool off. Several demonstrators needed medical attention.
Trump took to Twitter on Saturday morning to show his support for Immigration and Customs Enforcement amid calls from some Democrats for major changes to immigration enforcement.
Tweeting from New Jersey, Trump said that Democrats ‘‘are making a strong push to abolish ICE, one of the smartest, toughest and most spirited law enforcement groups of men and women that I have ever seen.’’ He urged ICE agents to ‘‘not worry or lose your spirit.’’
The Washington rally began with American Indian drums and a reminder that the story of most Americans began somewhere else.
A representative of the Piscataway Indian Nation addressed a crowd of thousands assembled in Lafayette Square on Saturday in Spanish, then English. Sebastian Medina-Tayac burned tobacco, an Indian prayer tradition, said a prayer, and then sang a indigenous-language song from Bolivia that means, ‘‘take courage.’’
‘‘We don’t believe in borders. We don’t believe in walls,’’ he said.
The rally ended with a march past the White House and the Trump International Hotel and onto the Department of Justice, where protesters affixed signs to the building gates:
‘‘We are better than this,’’ one said.
‘‘Las familias merecen estar unidos,’’ said another. (Families deserve to be united.)
There were many immigrants in the crowd — some whose families came long ago, and others much more recently arrived. Several near the stage cheered loudly and shouted ‘‘Bienvenidos,’’ or ‘‘Welcome,’’ as one of the latter, a woman named Jocelyn, took the microphone early in the day.
Jocelyn, who did not give her last name, said she came to the United States with her son from Brazil in August of last year. That’s when it happened to her, she said: The two were separated.
Held in a detention facility in Texas, Jocelyn didn’t know where her child was for the first two months, she said. Authorities told her he could be relinquished for adoption, she said, as audible gasps came from the crowd.
‘‘I spent many days sick and without hope,’’ she said in Spanish. ‘‘I wanted to join this fight to get my son back and for all the mothers who are suffering so far away from their children.’’
It took nine months to be reunited with her son, she said.
At each mention of the government, border patrol agents, or the Trump administration, the crowd erupted into chants of ‘‘shame, shame, shame.’’ Later, as they passed the Trump International Hotel, protesters booed and chanted ‘‘Vote him out.’’
Thousands in Washington waved signs: ‘‘I care, do you?’’ some read, referring to a jacket the first lady wore when visiting child migrants in Texas. Her jacket had ‘‘I really don’t care, do U?’’ scrawled across the back, and that message has become a rallying cry for Saturday’s protesters.
‘‘We care!’’ marchers shouted outside city hall in Dallas. Michelle Wentz, an organizer of the rally there, said opposition to the administration’s ‘‘barbaric and inhumane’’ policy has seemed to cross political party lines. Marchers’ signs read ‘‘Compassion not cruelty’’ and ‘‘November is coming.’’
Marchers also gathered in Albuquerque, Atlanta, Denver, Detroit, Indianapolis, Louisville, Houston, Minneapolis, Pittsburgh, Raleigh, Salt Lake City, and San Francisco. As groups came together in city parks and downtown squares across the nation, photos quickly started circulating on social media.
Other protesters converged on the international bridge that carries traffic between El Paso and Juarez, Mexico. They carried signs with slogans like ‘‘We are all immigrants’’ as they chanted ‘‘Love, not hate, makes America great.’’
Kentucky demonstrators gathered outside the Bowling Green office of Senator Rand Paul, a Republican, and massive crowds in Chicago chanted ‘‘Sí, se puede’’ (yes, we can).
Some protesters held signs calling for the dissolution of ICE, a recent rallying cry of lawmakers and immigration-rights groups. But that was not the purpose of Saturday’s march, organizers said.
‘‘We have three main demands,’’ said Anna Galland, executive director of MoveOn.org, which cosponsored the event. ‘‘Reunite families now, end family internment camps, and end the zero-humanity policy that created this humanitarian crisis and chaos in the first place.’’Material from Laura Crimaldi of the Globe staff and from the Associated Press was used in this report.