NEW YORK – The centennial commemoration of the Triangle shirtwaist factory fire became a rally for organized labor Friday, as hundreds marched and vowed to resist efforts to weaken unions in state capitals across the country.

U.S. Sen. Chuck Schumer, D-N.Y., drew loud cheers when he pledged to fight “right-wing ideologues” trying to curb worker protections.

The rally in New York’s Greenwich Village neighborhood took place outside the former Triangle factory building, which burned on March 25, 1911. Earlier, many people hoisting signs designed to look like shirtwaist blouses and bearing the names of the dead marched from Union Square several blocks south to the 10-story building, which is now part of New York University.

The Triangle fire killed 146 people and helped to galvanize the U.S. labor movement. The victims were mostly young immigrant women, many of whom jumped to their deaths to escape the flames. The tragedy prompted many improvements in fire safety across the country, such as sprinkler installation and laws mandating fire drills.

Days after the fire, 100,000 mourners marched in a funeral procession through the streets of New York, while another 250,000 lined the route. Their grief built support for the right of garment workers to unionize.

Many of the victims’ family members and descendants attended the ceremony Friday. Pete Doob, a laboratory worker from Columbia, Md., came to honor his great-aunt, 21-year-old Violet Schechter, who died in the fire just a week before she was to be married.

“There were no regulations back then and there was no union to enforce them. With neither of those, the workers didn’t have a chance,” Doob said.

Speakers repeatedly criticized Wisconsin Republican Gov. Scott Walker, who pushed through legislation earlier this month to eliminate public workers’ right to collective bargaining. The new law has been temporarily blocked by a county judge.

Several other Republican governors, citing their states’ dire money problems, have made similar efforts to weaken public employee unions, saying the pension and benefits unions have negotiated in the past are unsustainable over time.

U.S. Labor Secretary Hilda Solis, who spoke at the ceremony, offered her support for unions pushing back.

“Today we honor workers in communities all across this great country protesting loudly the actions to strip them of collective bargaining — of their right to have a voice in the workplace. We applaud you,” Solis said.

Schumer went further, saying Walker and others “want to drag our nation back to 1911.”

“Today some on the far right want to rob workers of their hard-earned collective bargaining rights. They want to fray the social safety net under the false pretense of fiscal austerity,” he said.

President Obama, in a proclamation on the 100th anniversary of the fire, urged people across the country to participate in ceremonies honoring the workers who died in unsafe conditions. “Working Americans are the backbone of our communities and power the engine of our economy,” he wrote.

At the rally, Cybele Locke, a historian from New London, Conn., said she believed many workers still face unsafe conditions.

Chuck Helms, a representative of the Hudson County Labor Council of New Jersey, said he had come to the ceremony because he believed workers’ rights were fading.

“I cannot let my children or my grandchildren go back to that time,” Helms said. “You know we are moving back. Not just unions, middle class in general is moving back in that direction. America has got to get out and protest.”