They carried signs with slogans like "We are all immigrants" as they chanted "Love, not hate, makes America great".
Attendees came to support three main objectives: reuniting families separated at the border, ending family detention and stopping the Trump administration's "zero humanity" immigration policy, as protesters called it.
Some are immigrants themselves or were raised in immigrant households. "I am here as a human being with a beating heart, who can feel pain, who understands compassion and who can easily imagine what it must feel like to struggle the way families are struggling right now". The actress gave an emotional speech at a Families Belong Together rally.
The Rev. Elizabeth Grasham, 34, attended a rally in Houston, where she serves as pastor of Heights Christian Church. "We need to provide for these children", she said.
Jimenez said her organization is asking "Congress to stop Trump's deportation force and ensuring that as the administration asks for more money to target community with ICE and border patrol agents, we say no and abolish and defund them". "It's deeply anti-Christian and absolutely anti-Christ".
Elaine Alvarez, 37, said she joined family members at a rally at Foley Square in NY to break stereotypes about immigrants being criminals.
Trump has made fighting immigration - both illegal and legal - one of the most sacred mantras of his fiercely US-centered policy agenda.
Casey, whose re-election campaign has accused Barletta for flip-flopping on the issue, said in a statement, "The policy of separating children from their families and housing them in cages is straight from the pit of hell".
Akossiwa Lawrence, 36, and daughter Delilah, 2, attended a rally in Washington to show solidarity with other immigrants.
DW's Michael Knigge met with Krzystof Sadlej from New York City, who had emigrated with his family from Poland when he was a boy and come to the USA under the diversity visa program that Trump wants to abolish. "It's heartbreaking", she said. "So I'm very concerned about this".
Madison Ramsey, 23, of Harrisburg, came with her friend Rachel Parthemer, 22, who traveled from Williamsport to participate in the rally.
"Seeking safety is not a crime", another said. It represents nannies, housekeepers and caregivers, many of whom are immigrants. "My mom and I are protesting because we know firsthand the difficulties families face when escaping hostile environments - usually ones the U.S. played a role in creating".
Widespread backlash over children being taken from their parents led President Donald Trump to reverse course last week, but immigrant advocates continue to call the government's hard-line policies toward migrants and asylum seekers harmful and "racist". She works at the Alaska Resilience Initiative, which does work addressing childhood trauma. "There are no words".
"It's thinly-veiled racism", Dorothy Carney, a 59-year-old middle school French and Latin teacher, told AFP at the Washington rally.
Hoplamazian, 39, said the Bible teaches that it is important "to stand up for those treated unjustly" and that Sessions committed "theological malpractice" when he used a snippet of verse to justify separating families.