Dawoud Bey and William H. Johnson

The Smithsonian American Art Museum’s exhibition of works by Dawoud Bey and William H. Johnson is small—just seven large photographs by Bey and one painting by Johnson—but they offer a convincing artistic portrayal of the Underground Railroad. Johnson’s 1944 oil on paperboard, “Swing Low, Sweet Chariot,” keys off the eponymous spiritual, which, according to some accounts, was written with the Underground Railroad in mind. The painting depicts elongated figures, including a man escaping slavery, a horse-drawn chariot dipping low, and a series of “angels” who are said to represent Ripley, Ohio, a key station along the trail to freedom. Even more evocative is Bey’s series of photographs from 2017, which pair silvery water and enveloping woods amid an encroaching darkness. The gloom that pervades Bey’s images effectively conveys the challenge of seeking a path to freedom in the twilight. But while his photographs’ dark hues communicate an overall murkiness, one image, “Untitled #18 (Creek and House),” expertly pairs thick brambles against a distant house, a tableaux rendered so precisely that it almost shimmers into three-dimensionality. Through Aug. 8 at the Smithsonian American Art Museum, 8th and G Streets NW. americanart.si.edu. Free.