More than 500 people, including at least one member of Congress, were arrested and escorted from the Philip A. Hart Senate Office Building on Thursday after staging a sit-in during a women-led march against the Trump administration’s “zero-tolerance” approach to illegal immigration.

The United States Capitol Police charged approximately 575 people with unlawfully demonstrating, a misdemeanor punishable by a $50 fine, according to a police spokeswoman. Those arrested included Representative Pramila Jayapal, Democrat of Washington, and the actress Susan Sarandon. Organizers said more than 2,500 women from 47 states participated in the protest.

Senator Tammy Duckworth, Democrat of Illinois, spoke to the protesters with her 11-week-old daughter, Maile Pearl Bowlsbey, strapped to her chest. Other Democratic lawmakers also appeared with or spoke to the demonstrators, including Senator Kirsten Gillibrand of New York, and the Representatives Nydia M. Velázquez of New York and Sheila Jackson Lee of Texas.

“We’re standing up for the real American values, the values that we as a nation welcome immigrants, we as a nation are stronger because of our diversity and we as a nation certainly do not rip families apart,” Ms. Duckworth said in a conversation with a group of protesters posted to Twitter.