A reconstructed tenant farmer’s house from a tobacco farm near Bowie, Maryland, is part of a exhibition titled “The Hall of Everyday Life in the American Past” at the National Museum of American History in Washington, D.C. ( National Museum of American History/Smithsonian Institution)

Whatever happened to the 20 or so furnished period rooms once on the second floor of the National Museum of American History? When I visited the museum shortly after the renovation that also removed the central Foucault pendulum, most of these rooms were gone. They ranged from the 18th century to the mid-20th century, from a Gold Rush kitchen to a New England 18th-century parlor, a Brooklyn dining room of 1910, an adobe room from New Mexico and many more.

Betty Walters, Rockville

“History is all about change over time,” said Bill Yeingst, a supervisory curator at the National Museum of American History.

He was talking broadly about how museum exhibits are put together, but he could just as well have been talking about the exhibits themselves. An exhibit provides not just a snapshot of the period from the past it is trying to explore, but also says a lot about the period in which it was created. A 1969 exhibit about the 1849 California Gold Rush says something about both eras. And when we ponder that exhibit in 2013, we add another layer of complexity.

But to answer the easy question first: This particular exhibit, which included display cases as well as entire rooms, was taken down around 1980. Bill said it actually predated the history museum, having first been installed in 1957 in the National Museum of Natural History. It was among the inaugural exhibits when American History — known then as the Museum of History and Technology — opened in 1964.

The exhibit was called the “Hall of Everyday Life in the American Past.”

That name likely strikes us as quaint now, old-fashioned, and yet the exhibit marked a new way of looking at American history. Its creator was C. Malcolm Watkins, a Harvard-educated curator who had worked at the Wells Historical Museum in Massachusetts, precursor to Old Sturbridge Village.

“His passion was documenting the neglected history of the everyday lives of ordinary Americans,” Bill said. “It was more an anthropological framework to an understanding of what was Euro-American history.”

Bill said this approach greatly influenced other curators and historians, who, for example, started studying probate inventories to see what objects Americans owned and how they used them.

Over time, new movements influence historians, who formulate new ways of looking at old things. Audiences change, too.

“Usually we take exhibits down because we have something else we’re planning to install,” Bill said. “Things may get incorporated into a new exhibition and a new framework of interpretation.”

The exhibit that followed the “Hall of Everyday Life” was “After the Revolution: Everyday Life in America.” Said Bill: “We sought to broaden the representation of neglected groups: enslaved Americans, Native Americans, women, the working poor. . . . That became a more inclusive exhibition, more so than the Watkins exhibit.”

Old favorites often vanish from museums. American History’s mesmerizing Foucault pendulum went bye-bye in 1998. (Foucault wasn’t American, after all.)

Answer Man still gets misty-eyed remembering “The Helping Hand,” a painting by Emile Renouf of an old man and a small girl rowing a boat. On loan from the Corcoran Gallery of Art, it hung for years in the Renwick Gallery’s Grand Salon. The Corcoran sold it to a private collector in 1988 for $137,500, though it was on display at the Renwick in 1994.

Then there’s the massive blue whale that once swam in the air at Natural History. When the Sant Ocean Hall was opened in 2008, the whale was gone. In its place was a replica of Phoenix, aNorth Atlantic right whale, accurate right down to the barnacles on her snout.

“The blue whale is represented in a lot of museums,” explained Natural History’s Kelly Carnes. “The North Atlantic right whale was different.”

It had a new story, not just about cetacean biology but about how humans hunted right whales nearly to extinction.

The blue whale was dismantled and is in storage. So are the bits of American History’s “Hall of Everyday Life,” minus any parts used in other displays.

“The display pieces become historical objects themselves,” Kelly said.

Such is the circle of life in Washington’s museums.

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