Clarence King's Survey, undertaken between 1867 and 1872, covered a vast swath of terrain, from the border of California eastward to the edge of the Great Plains. It was the first survey to include a full-time photographer--Timothy O'Sullivan--who produced about 450 finished photographs in large-format and smaller-format stereographs. O'Sullivan's images convey a distinct individual quality of perception, at once direct and laconic, as well as...