NEW YORK — The Fight for $15 campaign that began with fast-food workers expanded in size and scope Wednesday to include a range of workers who say their meager pay is a form of economic injustice.

Organizers said demonstrations were planned for more than 230 U.S. cities and college campuses, as well as dozens of cities overseas.

In New York City, more than 100 chanting protesters holding signs with messages like “We See Greed” gathered outside a McDonald’s around noon, prompting the store to lock its doors to prevent the crowd from taking over the store.

Demonstrators laid on the sidewalk to stage a “die-in,” which became popular during the “Black Lives Matter” protests after recent police shootings of black men. Several wore hooded sweatshirts that said “I Can’t Breathe,” a nod to the recent death of a black man in New York City who was put in a police chokehold.

Timothy Roach, a 21-year-old Wendy’s worker from Milwaukee, Wisconsin, who traveled to New York for the protests, said the police brutality black men face is linked to how they’re viewed by employers and the lack of economic opportunity they’re given. He said the protests were important to send a message to the people in charge at companies like McDonald’s.

“If they don’t see that it matters to us, then it won’t matter to them,” Roach said.

In Jackson, Mississippi, around 30 people demonstrated in a McDonald’s before being kicked out. Organizers said about half of them were McDonald’s workers, although a representative for McDonald’s Corp. said its local team found only one participant was a McDonald’s worker from the region. One of the demonstrators was arrested for trespassing.

Protesters also gathered outside McDonald’s restaurants in cities including Denver and Los Angeles, after demonstrations got off to an early start in Boston and Detroit on Tuesday. In Albany, New York, about 150 people marched and demonstrated outside a McDonald’s.

The Fight for $15 campaign is being spearheaded by the Service Employees International Union and began in late 2012. Since then, organizers have used the spotlight to rally workers in a variety of fields, with adjunct professors being the most recent to join in Wednesday.

Kendall Fells, organizing director for Fight for $15 and an SEIU employee, said McDonald’s remains a focus of the protests and that the company’s recently announced pay bump shows fast-food workers already have a de facto union.

“It shows the workers are winning,” he said.

McDonald’s earlier this month said it would raise its starting salary to $1 above the local minimum wage, and give workers the ability to accrue paid time off. It marked the first national pay policy by McDonald’s, and indicates the company wants to take control of its image as an employer more than two years after the protests began. But the move only applies to workers at company-owned stores, which account for about 10 percent of more than 14,300 locations.

That means McDonald’s is digging in its heels over a central issue for labor organizers: Whether it has the power to set wages at franchised restaurants.

McDonald’s, Burger King and Wendy’s say they don’t control the employment decisions at franchised restaurants. The SEIU wants to change that and hold McDonald’s responsible for labor conditions at franchised restaurants in multiple ways, including lawsuits.

In a statement, McDonald’s said it respects the right to “peacefully protest” and that its restaurants will remain open Wednesday. In the past, it said only about 10 to 15 McDonald’s workers out of about 800,000 have participated.

In a recent column in The Chicago Tribune, McDonald’s CEO Steve Easterbrook described the company’s pay hike and other perks as “an initial step,” and said he wants to transform McDonald’s into a “modern, progressive burger company.”

But that transformation will have to take place as labor organizers continue rallying public support for low-wage workers. Ahead of the protests this week, a study funded by the SEIU found working families rely on $153 billion in public assistance a year as a result of their low wages.

Last year, more than a dozen states and multiple cities raised their minimum wages, according to the National Employment Law Project. Wal-Mart Stores Inc., which has also been targeted with protests for higher wages and better treatment for workers, recently announced pay hikes as well.

Robert Reich, former Labor secretary and a professor of public policy at the University of California, Berkeley, said stagnating wages for lower-income workers are helping change negative attitudes about unions.

“People are beginning to wonder if they’d be better off with bargaining power,” Reich said.