WASHINGTON – Roger Kennedy, the director of the Smithsonian’s National Museum of American History, who transformed the stodgy repository often called “America’s attic” into a vibrant display that enshrined pop-culture memorabilia even as it confronted some of the most shameful moments in the country’s past, died Thursday in Rockville, Md. He was 85.

He had melanoma, said his wife, Frances Hefren Kennedy.

Kennedy, who served as director of the National Park Service after leaving the history museum in 1992, took an unusual path to the top of a major American museum. He held many jobs — Washington correspondent for NBC in the 1950s, banker, vice president of the University of Minnesota and executive with the Ford Foundation in New York.

He arrived in 1979 to the Museum of History and Technology, as the American history collection was then known, without any experience in museum administration but with a visceral passion for the past.

When Kennedy began working for the Smithsonian Institution, secretary S. Dillon Ripley was concerned with strengthening its mass appeal. Like Ripley, Kennedy cared most about drawing people into the museum and persuading them to stay a while.

Kennedy led what current interim director Marc Pachter called the museum’s “golden age.” The building’s name changed to its current one, a move that reflected Kennedy’s aspiration to house more than a staid collection of collections. He reorganized the trove of artifacts — ranging from stamps to inaugural gowns and machines — to present a broader narrative of the United States.

Exhibits and acquisitions during his tenure included the chair from which the fictional Archie Bunker shot off his bigoted mouth on the television show “All in the Family,” forcing viewers to confront an ugly side of American culture in the 1970s; the set of the “M.A.S.H” television show that helped families talk not only about the war in Korea, but also the one in Vietnam; and one of the red cardigans Fred Rogers donned every time he asked millions of American children if they would be his neighbors.

Some critics did not warm to the emphasis on pop-culture items, questioning whether the ruby slippers from “The Wizard of Oz” merited a place in the marble halls of a museum that also grappled with slavery and racism.

Kennedy defended the popular items, saying his hope was to entice people with the fun stuff.

In style, Pachter said, Kennedy used the “principles of drama” to make the museum more engrossing. He hired a theatrical designer from the Metropolitan Opera to dream up a display for the flag that inspired “The Star-Spangled Banner.” Once an hour, lights illuminated the flag while the national anthem’s melody rang out over speakers.

In substance, he favored untold history, particularly the narratives of minorities long overlooked by many museums.

Leading up to the Constitution’s bicentennial in 1989, the museum opened the exhibit “A More Perfect Union,” about the internment of the Japanese by the U.S. government during World War II.

In the 1987 exhibit “Field to Factory,” the museum chronicled the northward migration of African Americans during the first half of the 20th century. Visitors entered a life-size train station waiting room through two doors labeled “White” and “Colored.” Writing in The Post, critic Lon Tuck called the show an “exhaustive” display that documented “a vital — and somewhat neglected — portion of American social history.”

After 13 years with the museum, Kennedy moved to the National Park Service, which he led from 1993 to 1997.

He distinguished himself from many previous directors by wearing the NPS flat hat, gray shirt and green trousers in a show of solidarity with the rank and file.

His most significant achievement was helping the park service see itself not only as the custodian of the magnificent parks of the West, but also as the keeper of hundreds of historic landmarks famous and unknown.