States are appealing a judge’s decision to quash their Facebook antitrust case.

WASHINGTON — Nearly four dozen states on Friday asked a federal appeals court to reconsider an antitrust case against Facebook that a judge dismissed last year.

In June, Judge James E. Boasberg of the U.S. District Court for the District of Columbia said states had waited too long to file a lawsuit after some of the deals under investigation were closed.

The plaintiffs, led by Attorney General Letitia James of New York and which includes the District of Columbia and Guam, argued in their appeal that states have more latitude than private plaintiffs in bringing lawsuits. They also argued that it was in the public interest for the Attorney General to hear the antitrust complaints against Meta, Facebook’s parent company.

The states’ central claim is that Facebook has predatorily taken over competitors — most notably Instagram in 2012 and WhatsApp in 2014 — to crush the competition. They also claim that Facebook harmed rivals like Vine by blocking them from accessing data and tools on its platform. That hurt consumers, who got more competition and alternative services in social networks, the states say.

“Again and again, the social media giant has used its market dominance to bankrupt small businesses and reduce competition for millions of users,” said Ms. James. “We are filing this appeal with the support of nearly every state in the nation, as we will always fight attempts to stifle competition, reduce innovation, and diminish privacy protections, even when faced with a goliath like Facebook.”

Chris Sgro, a spokesperson for Meta, said: “We believe that the court’s decision to dismiss the states’ complaint was correct, and there are no grounds for reversing that decision.”

Legal pressure against Meta has increased in recent days. The state’s appeal comes days after a Mr. Boasberg authorized a revised version of a similar antitrust lawsuit by the Federal Trade Commission. The FTC argued that the company used a “buy-or-bury” strategy in its Instagram and WhatsApp acquisitions to create a monopoly on social networks.

Mr. Boasberg was initially skeptical of both lawsuits, but for different reasons. He said federal regulators had not provided enough evidence to support some of his fundamental claims, such as Facebook having a monopoly. This week, he said those regulators had cleared that bar in a revised suit.