Since the 1980s, the American artist Stan Douglas has specialized in making art out of moments, as he puts it, when “history could go one way or the other.” Across different media, Douglas has portrayed conflicts that linger unresolved after they are out of view. The exhibition “Ghostlight” is no different. Titled for the single light that illuminates a theater stage during the night—for both safety and superstition (it allows spirits to “perform”)—the installation features D. W. Griffith’s highly controversial, 1915 film The Birth of a Nation. In a twist, Douglas has included the context that Griffith conveniently omitted: the slave trade and its involvement with the real birth of the nation. —Andie Blaine