"The family that founded Wal-Mart has some of the richest people in the world," said protester Zazette Scott of Upland. "Their employees have been very good to them. We are just asking them to be good to their employees. Nothing more."

The Change to Win labor federation of seven unions, which broke away from the AFL-CIO last year to form the nation's second largest labor group, said Wal-Mart epitomizes a business model of low pay and benefits that harm the middle class. The AFL-CIO has about eight million members.

"You can't really talk about these issues without talking about Wal-Mart. Wal-Mart drags everybody down, but they are not the only bad actor out there," said Carole Florman, spokeswoman for Change to Win.

It is the federation's first national rally targeting Bentonville, Ark.-based Wal-Mart and part of a broader campaign called "Make work pay" aimed at raising living standards for workers, she said.

Wal-Mart called the rallies a political stunt that ignored the fact that it created 225,000 U.S. jobs last year and provides career opportunities and above-average pay and benefits for the retail sector. It also says it saves its customers, including working families, about $2,300 a year.

"We are an economic engine. Wal-Mart is good for the communities we serve," said company spokesman Dan Fogleman. He added that Wal-Mart recently announced it would help small businesses grow around 50 stores it plans in blighted urban areas.

The rallies were organized together with WakeUpWalMart.com, a political campaign group started a year ago by the United Food and Commercial Workers union to pressure the retailer to raise pay and benefits and improve working conditions. The UFCW is part of Change to Win.

Paul Blank, campaign director for WakeUpWalMart.com, targeted Wal-Mart's health-care insurance, which he said failed to cover 57 percent of its work force, or 775,000 employees. That estimate is based on earlier Wal-Mart numbers, the group said.

Wal-Mart's own latest count from February was that 615,000 employees, or 46 percent, were enrolled in company health plans as of January.

Covina resident Carlos Soto also said that Wal-Mart does not use organized employees for building projects, which protesters said causes more people to work without adequate pay or health insurance.

The unions also cited an internal Wal-Mart memo, which became public last fall, that said 46 percent of the children of Wal-Mart workers were uninsured or on public health care.

Wal-Mart has defended its health care coverage and twice since October has announced improvements, including shorter eligibility periods for part-time workers, coverage for their children, lower premiums between $11 and $23 a month and reducing prescription co-pays to $3 from $10.

The announcements reflect growing outside pressure on the company, which was exhibited in the state of Maryland recently. There, the state's legislature passed a law that requires companies with more than 10,000 Maryland employees to spend at least 8 percent of their payroll on employee health care or pay the difference into the state's Medicaid fund.

The Change to Win federation is made up of the carpenters' union, the laborers' union, the service employees, the Teamsters, United Farm Workers, UFCW and UNITE Here.

Staff writer Ben Baeder contributed to this report.