Across Boston on Monday, elected officials and activists called for social justice and equality of opportunity, evoking the legacy and principles of Rev. Dr. Martin Luther King Jr. in speeches and demonstrations around the city.

On the national holiday to honor King, a host of elected officials called for equal access to housing, jobs, health care and education before the annual breakfast of nearly 1,000 at the Boston Convention & Exhibition Center. Later in the day, demonstrators marched through the city down William J. Day Boulevard, protesting police action and calling for a higher minimum wage.

Although the breakfast-goers also heard from Governor Charlie Baker Mayor Martin J. Walsh, and US Senator Elizabeth Warren, it was US Senator Edward J. Markey who brought the crowd to its feet.

The Bay State’s junior senator delivered a passionate soliloquy that called for reform on issues that ranged from voting rights to drug addiction to wage disparity to access to education.

“It is no wonder that so many families who try to climb to the mountain top feel like they’re just walking in place,” said Markey, echoing words from the speech King delivered the night before he was assassinated in Memphis in 1968.

The senator called the three strikes prison sentencing law a “historic mistake” and the response to heroin and prescription drug addiction a “national disgrace.” He demanded closure of three gun purchasing loopholes and said the fact that African Americans die from certain diseases at higher rates is “shameful.”

“Black lives matter, black voices matter, black votes matter,” Markey said, his voice quavering after he had powered through a list of policy issues. Like a minister in the pulpit, Markey followed each demand with the line “we have more work to do.”

Markey also called for justice for victims of police brutality across the country this year, saying King’s legacy was forgotten in the events that took place in Baltimore, Chicago, Cleveland and Charleston. As he closed, Markey commended the governor and mayor for their work convincing General Electric to relocate its headquarters to Boston, and said local leaders “want in this city for GE to stand for greater equality.”

Baker used his remarks to call for cooperation in politics between people of different viewpoints, saying “politics is often about who or what you’re against, not what you’re for.”

Walsh said Boston is “still dealing with the lingering effects of our divided history,” and called for more income and housing equality.

Local clergy, nonprofit leaders, community activists and politicians filled the seats on Monday morning for the annual breakfast, where they served waffles and eggs. Representatives from state agencies, including the Massachusetts Commission Against Discrimination, also attended, along with employees from local companies including Mass Mutual and Partners HealthCare.

Boston Police Commissioner William B. Evans, who attended the breakfast, said in a brief interview after the speeches that his department works hard to build trust in the community so citizens will help police stop gun violence.

“I think most of the people in the community trust us and respect us, but there’s always room for improvement,” Evans said

Hours later at the other end of South Boston, a throng of about 150 mostly young people held signs, megaphones and drums to honor King’s legacy Monday afternoon.

“It’s our job to stand up for all people but especially the marginalized and struggling people, especially in Boston,” said Jordan Zepher, 24, of Boston.

State troopers Monday afternoon helped block traffic while demonstrators marched in blowing snow from through Kosciuszko Circle and up Columbia Road.

“Whose city? Our city! Whose streets? Our streets!” protesters yelled, carrying signs that decried institutional racism, called for rights for immigrant workers and endorsed US Senator Bernie Sanders for president.

Sofiane Tiken, 20, of Malden, braved the cold to protest Islamophobia.

“You can’t judge someone by their looks,” said Tiken, who is Muslim and said he has experienced discrimination in Boston.

Peri Levin McKenna, of Boston, also attended, with her dog, Ulysses, who wore a homemade “End Mass Incarceration” sign.

Stepping aside from the group of protesters while Ulysses hunted for a good bush, Levin McKenna said she works at a community health center in Uphams Corner and witnesses inequality every day.

“I just couldn’t stay home,” she said, disappearing back into the throng of protesters.