Attendees of the protest, which took place at Lafayette Square Park in Washington, D.C., told NBC News that the treatment of Kilmar Abrego Garcia, who the Trump administration says was mistakenly deported to El Salvador, was among the issues that led them to participate in the demonstration.

A series of nationwide protests against President Donald Trump and his policies are set to take place on April 19 in all 50 U.S. states, while other protests will take place in upcoming days.

Protesters hit the streets in all 50 states and rallied outside the White House Saturday. They were targeting Trump administration policies in a “50501 National Day of Action."