WALKER EVANS casts a lengthening shadow over contemporary photography. For well over half a century, what he called his “documentary style” — images so deadpan they seem not to exhibit any style at all — has shaped several generations of artists, especially here and in Germany. His rigorous artlessness, along with a keen historical conscience, permits broad latitude of subject matter within a straitening aesthetic. Once you get Evans (a long process for many), other photographers can look like preening or bumptious show-offs.

William Christenberry has moved in and out of the Evans penumbra all his life. Born in the same year (1936) and in the same region (Hale County, Ala., and its environs) where Evans and James Agee initiated the project that became “Let Us Now Praise Famous Men,” Christenberry grew up among the same sorts of places and people — tiny wooden Baptist churches, roadhouse shacks, tenant farmers — that those two visitors from up north turned into icons of the impoverished rural South.

His adoption and revision of Evans’s heritage makes Christenberry an unusual and valuable artist. Reworking rustic material that to him always meant “home” (even after 1968, when he settled in Washington), he has returned again and again to Alabama and produced a uniquely obsessive, personal record of a Southern landscape — in photographs, drawings, paintings and sculptures — that miraculously never succumbs to nostalgia. It is fitting that his retrospective exhibition, for which “William Christenberry” serves as a catalog, recently inaugurated the reopening of the Smithsonian American Art Museum in the nation’s capital. (The book includes 130 plates, and essays by Walter Hopps, Andy Grundberg and Howard N. Fox.)

Modesty and discretion characterize everything Christenberry touches. His best-known works are his small color photographs (some no more than three inches square) of a single building, often an abandoned or boarded-up house, in a woodland setting. Evans once famously disdained color as “vulgar” in contrast to the austerity of black and white. But Christenberry isn’t trying to sell us anything. His saturated palette of brick reds, kudzu greens and dirt browns, as well as the miniature scale of his prints, harks back to the vernacular tradition of picture postcards rather than to the American sublime.

Trained as a painter in the late 50’s, Christenberry demonstrates in many of his photographs from the 60’s and 70’s an eye for the commercial semiotics that delighted pop artists at the time. He can’t resist battered or fading road signs and crooked hand-lettered messages. His serial images of isolated buildings, viewed year after year in various seasonal lights and states of decay, also have affinities with minimalism. He presents many of these structures as though they were inscrutable, functionless pieces of sculpture. They stand with doors and windows shut, uninviting, even a little hostile to outsiders. By now he is one himself, and that status helps him resist the lure of sentimentality.

Humans rarely appear in Christenberry’s work; he prefers to examine our totems and traces. This emotional neutrality can be disconcerting when he handles volatile Southern material. The drawings and dolls he has made since 1962 based on the Ku Klux Klan — he used a hidden camera to photograph rallies in Memphis — may not go far enough for some as either personal exorcism or historical critique. Unlike Philip Guston, who spiked his paintings in the 60’s and 70’s with satirical Klan imagery, Christenberry holds the meanings of his fetishized figures close to the vest.

If the satiny robes on his Klansmen seem too lovingly sewn, perhaps that is because he is an old-fashioned artist who can’t help taking pains with whatever he makes. Instead of heartfelt confessions, he channels his autobiography through formalist means. What unites the peaked roof of an Alabama warehouse, a K.K.K. hood and sculptures of white obelisks that resemble the Washington Monument is their conical geometry — an understated device that allows him to show the thread that in his mind connects his old home with his new.

Time and weather ceaselessly eat away at everything born or built on earth — a melancholy fact notably pronounced in the South, where corrosive wet summer heat abets nature’s master plan to reclaim any cleared terrain. In his recent work — ink drawings of pine straw and sculptures with squash gourds — Christenberry has paid tribute to this lush environment without mourning his boyhood.

The kudzu devouring a vacant cabin in a 2004 photograph is a science fiction monster that can turn anything into a Chia Pet. Neither good nor evil, the vine is simply a nuisance of life in this part of the country. Christenberry’s focus on the habitats and hangouts of the poor, blacks and whites, is similarly nonjudgmental. These places weren’t constructed to last for the ages and aren’t likely to be missed, except by those who filled them for a few years or decades. Still, he treats them with respect, charting their alterations and passings. Paying careful attention to surroundings that would otherwise be forgotten or unremarked upon can be its own political statement.

What Christenberry absorbed from Evans he has transmitted to others, like the Cuban-American team of Eduardo del Valle and Mirta Gómez, whose photographs of ephemeral dwellings in the Yucatán, made over many years, owe a lot to these serial studies of Hale County. Photography is the ideal medium for looking closely at slowly changing things. As people everywhere rush to transform the world, knocking down humble buildings in order to erect bigger ones, photographs, symbols of evanescence, may one day be the only proof that something else was ever there.

Richard B. Woodward is an arts critic and journalist. He contributes the Armchair Traveler book review column to the Travel section of The Times.