John C. Truesdale, a stalwart of the National Labor Relations Board who was called back from retirement to serve as chairman and tackled a severe backlog of cases at the core of the agency’s functions, died of cancer July 3 at a hospital in Martinsburg, W.Va. He was 89.

Mr. Truesdale, who joined the board in 1948 as a field examiner, served two decades as executive secretary, the highest staff position. From 1977 to 1996, when he retired, he was on the five-member board overseeing the federal agency.

In 1998, he returned from retirement at the request of President Bill Clinton to serve as chairman, and he was confirmed by a unanimous Senate vote in 1999.

Mr. Truesdale succeeded William Gould, a professor and labor law expert frequently described as combative. Gould also drew ire from many quarters for his tendency to publicly express his opinions on matters before the NLRB.

At the time of Mr. Truesdale’s appointment to chairman, the labor board — once nicknamed the “Rip Van Winkle of federal agencies” for its struggle to resolve cases in a timely fashion — had an estimated 700-case backlog, down from an all-time high of 1,700 during the Reagan administration.

“I come in with no preconceived notions of policy, but to reduce the amount of time it takes to issue decisions,” Mr. Truesdale told The Washington Post in 1998.

James Gross, a labor historian at Cornell University, said the case clean-up was Mr. Truesdale’s major contribution.

“John wanted to take care of business,” Gross said in an interview. “His concern was not just with the number of cases, but with the age of them, too. He wanted to deal with that because that’s the work the board was supposed to be doing. It was extremely important.”

Unlike Gould, Gross said, Mr. Truesdale kept agency business out of the limelight.

John Cushman Truesdale was born July 17, 1921, in Grand Rapids, Mich., and grew up in Grinnell, Iowa. He served in the Coast Guard during World War II.

He was a 1942 graduate of Grinnell College and received a master’s degree in industrial labor relations from Cornell in 1948. In 1972, he graduated from Georgetown University’s law school.

Mr. Truesdale moved from Bethesda to the Baywoods of Annapolis assisted living community in 2005. Earlier this year, he relocated to Martinsburg to be near family.

Survivors include his wife of 54 years, Karin Nelson Truesdale of Martinsburg; four children, Jack Truesdale of Longmont, Colo., Charles Truesdale of Louisville, Colo., Andrew Truesdale of Bethesda and Margaret Quigley of Martinsburg; two sisters; and 11 grandchildren.