Established in 1949, the National Trust for Historic Preservation concentrates most of its efforts on advising and assisting local preservation groups. But it owns 17 properties outright, and in Of Houses & Time William: Personal Histories of America's National Trust Properties, William Seale tells the story of these residences. Rather than devote a chapter to each building, Seale, an architectural historian, tells his story chronologically. He begins with three colonial mansions—Drayton Hall in South Carolina, Cliveden in Philadelphia, and Montpelier in Virginia—and the families that owned them, each deciding whether to remain loyal to the king. Then, era by era, he evokes the sweep of American history by examining the changes taking place at the those houses.

As the United States enters the First World War, for example, the now-famous gardens at Filoli, in Woodside, California are just being planted, while at Chesterwood—Daniel Chester French’s home in Stockbridge, Massachusetts—costume balls come to an end: “In Margaret French’s photo albums, the beaux dressed the year before in summer white have reappeared in army uniforms,” and at Montpelier, James Madison’s home in Virginia, now owned by William du Pont, “a Browning machine gun was brought out from Wilmington, and du Pont and his son tested it with vigor; the windows rattled and bullets riddled the garden wall.”

Described in this way, the houses take on a character and consequence that extends beyond any individual owner, and it is disturbing to realize how close some of them came to destruction. Commodore Stephen Decatur’s 1818 house on Lafayette Square in Washington, D.C., for example, narrowly escaped being razed by the federal government to make way for new office space. (Dolley Madison’s house, also on the park and, for decades, the social center of the capital, was not so lucky.) And when a house that Frank Lloyd Wright designed as a model of an inexpensive residence for the middle class was threatened by an interstate highway, the only way to save it was to move it out of the way.

These houses, now carefully restored and maintained, are all open to the public. Old Houses, by contrast, features unrestored properties, many of them still in private hands. Among them are a summer cottage in Brunswick, Maine, a town house in Boston, plantation houses in North Carolina and Louisiana, an adobe in Taos, and a Frank Lloyd Wright house in Los Angeles. In these interiors, plaster is cracked, paint evanesces from walls and ceilings, chairs sag, upholstery wants attention, but the past is present with almost mystical force.

In his book, Old Houses, Henry Wiencek tells the story of each house—its proud creation, its portion of romance and tragedy, its slow glide into disrepair. Some of the current owners seem bewildered by all the attention. Amos King, proprietor of the Chapman Hotel in North Blenheim, New York, isn’t sure how old any of the furniture is because it was all in place in