The National Labor Relations Board on Friday dropped its complaint against Boeing Co. over the 787 Dreamliner plant in North Charleston, ending a case that turned the Lowcountry factory into a national political fight.

The board’s acting general counsel, Lafe Solomon, said the International Association of Machinists asked to withdraw its charge after members ratified a new four-year contract with Boeing this week. Based on that request, the administrative law judge hearing the case dismissed the complaint and sent it back to the board’s regional office in Seattle. Regional Director Richard Ahearn approved the union’s written request Friday morning, and the case is now closed, Solomon said.

“This is the outcome we have always preferred, and one that is typical for our agency,” Solomon said in a statement. About 90% of meritorious NLRB cases are resolved by agreements between the parties or settlements before litigation ends, he said.

What the union got

Machinists in Washington state approved the contract Wednesday, The Herald of Everett reported. Under the deal, Boeing promised to build the new version of its 737 in Washington state, and the Machinists agreed to drop their allegation that Boeing opened the South Carolina plant to retaliate for past strikes, The Associated Press reported. The new 737 MAX will be built in Renton, Wash., according to The Herald.

About 74% of voting union members supported the contract, ABC News reported. “It is such a monumental, historic moment that is changing the relationship between Boeing and the Machinists,” union spokeswoman Connie Kelliher told ABC News.

Solomon told reporters that the complaint had always been about the loss of future jobs in the Seattle area, and that the new contract brings job security there and at the North Charleston plant, according to the AP.

“This case was never about the union or the NLRB telling Boeing where it could put its plants,” Solomon said on a conference call. “This was a question for us of retaliation, and that remains the law. If we were ever faced with a similar pattern, we might well issue a complaint.”

Boeing: never had merit

Boeing said it had argued from the start that the complaint should be dropped. “We have maintained from the outset that the complaint was without merit and that the best course of action would be for it to be dropped,” the company said in a statement reported by Aviation International News. “Today that happened.”

Boeing spokesman Tim Neale said the company was “grateful for the overwhelming support we received from across the country to vigorously contest this complaint and support the legitimate rights of businesses to make business decisions,” the AP reported.

The complaint, issued in April, accused Boeing of illegally retaliating against its Puget Sound Machinists for strikes when it placed a 787 assembly line in South Carolina, The Herald reported. Boeing denied the charge. The board had suggested that Boeing set up a second 787 line in Everett, Wash., to make up for the work, and Boeing had said that in that scenario it would have to close the South Carolina facility, according to The Herald.

Republicans had claimed the labor board was trying to dictate where a major company could do its business, The Herald reported.

Relief in South Carolina

South Carolina’s congressional delegation welcomed the news. “For the sake of the Boeing South Carolina workers, I’m pleased to hear the frivolous complaint that has put a cloud over their operations has been lifted,” said U.S. Sen. Lindsey Graham, R-S.C., according to the AP.

Sen. Jim DeMint, R-S.C., said agency officials who led the case should still “resign immediately,” the AP reported.

U.S. Rep. Tim Scott said the decision was “certainly great news for the Lowcountry after months of unneeded stress being placed on the backs of 1,100 hardworking South Carolinians,” in a statement reported by ABC News 4.

Gov. Nikki Haley has repeatedly called the labor board a “rogue agency,” The Herald reported.

House Oversight Committee Chairman Darrell Issa, who has been investigating the board’s handling of the case, called the outcome “a victory for the people of South Carolina and Boeing workers whose livelihoods have been in limbo throughout the course of this action.” He said his investigation of the board would continue, ABC News reported.

The committee’s ranking Democrat, Elijah Cummings of Maryland, said the deal was “a victory for American workers and a vindication of their rights under federal law not to be discriminated against,” and said he hoped the committee would end its inquiry, according to ABC News.

The plant’s next step

About 1,000 jobs were created at the new North Charleston plant, ABC News reported. Boeing opened the 787 final assembly building in June and said then that final assembly of the first South Carolina-built 787 would begin that summer.

A Boeing spokeswoman said in June that the company expects to deliver its first airplane from South Carolina in 2012. At full production, Boeing has said, the North Charleston plant will build three 787s a month.