According to the organisers, the group included children from Miami, New York, Colorado and the Washington D.C. area who began their journey to the capital last week to 'send a message' to the President, The Hill magazine reported.
They stopped in Atlanta and the Raleigh-Durham area in North Carolina before ending their trip here.
Under the slogan 'We belong together', the protesters on Thursday gathered at Lafayette Park, in front of the presidential mansion, to 'raise the community's awareness that we should be united'.
"The reason why I'm here is that the President wants to separate families. He shouldn't do it, because it's bad to do that. We need for him not to do it," seven-year-old Nayahuari Mesa, who was here with her three-year-old brother and parents from New York, told Efe news.
Her mother, Felicia Martinez said that Nayahuari was aware of the situation and, although fortunately, her husband was able to acquire permanent US residence just a month ago, after 12 years as an undocumented migrant, she wants to be part of the fight to prevent other families from suffering possible separation.
Legal immigrants and undocumented migrants, as well as families who were able to take advantage of the immigration relief plans pushed by former President Barack Obama, joined forces to make clear to the Trump administration that they were not going to give up.
Rosana Araujo, from Uruguay, came in the caravan that drove up from Miami, as part of the Women Working Together organisation, said that she is one of those immigrants without papers who could be separated from her US-born son.
"We came with our children, we're a group of fathers, mothers and kids who - in Easter Week - want to send a message: that family unity exists," Araujo, who has been in the US without papers for 14 years, told Efe news.
"Let the raids stop, let there be more protection for immigrants, for each community to become a sanctuary community, for our mayors, commissioners and representatives to support the community and not cooperate with the police," she said.
She was referring to the threats from the Trump administration against the so-called "sanctuary cities", which by municipal decision do not persecute immigrants based on their immigration status.
Both Latinos and African Americans, to shouts of 'Up with education, down with deportation', also joined the protest.
More than 11 million people are estimated to live illegally in the US, and about six million US-born children are at risk of being separated from their parents if the latter are deported.