Samuel J. Wagstaff Jr. (1921-1987) amassed an extraordinary collection of 26,000 photographs between 1973 and 1984, recognizing that photography was an undervalued art form on which he might have a profound impact as a collector. He was mainly attracted to photographs that stimulated his imagination, and his taste ran toward the idiosyncratic--images that surprised him chiefly because he had never seen them before. In choosing the 147 works...