Tens of thousands of demonstrators took to the streets under the banner "May Day Strong" in Washington DC and cities across all 50 states on Thursday, marking May 1 with widespread protests against the second-term policies of US President Donald Trump's administration.

In the nation's capital, demonstrators gathered at Franklin Square near federal buildings and marched to Lafayette Square at the gate of the White House, chanting slogans like "We Are the Majority, They Are the Minority" and "No Justice, No Peace", and waving handmade signs.

Messages ranged from "Protect Medicaid and Social Security" to calls for union protections and immigrant rights, reflecting the diverse coalition mobilized by the 50501 movement since its emergence from online forums earlier this year.

The number 50501, symbolizing "50 states, 50 protests, 1 movement", as a decentralized grassroots movement, largely organized the "National Day of Solidarity" protest across the US, mostly on May Day.

The protest events, right after the administration's first 100 days, merged traditional International Workers' Day themes with opposition to the second Trump administration's actions on immigration, federal agencies, social programs and perceived threats to democratic norms.

Many participants, like "DH", a protester from Northern Virginia who asked to be identified only by his initials, described their presence as a defense of fundamental rights. He emphasized concerns over "wealth inequality, protection of democracy and the people's right to speak their voice, no matter what".

DH, who is a teacher, specifically connected the May Day protest to the historical struggle for labor rights. "Part of the Trump administration is very anti-labor union, and the unions are what gave us weekends and holidays and benefits, protected people from child labor, protected people from having an unsafe workplace," DH told China Daily. He said that the labor unions are one of the few remaining groups in society that can push back.

"I think that the greatest notion is [against having] more than 1 percent of the population control 99 percent of the wealth in America," he said. "It is nice to see that everybody's rallying around that."