Though it seems impossible to imagine today, there was a time, just thirty years ago, when major exhibitions of historical photographs were rare, and their sumptuously reproduced, oversize catalogues even rarer. With the exception of John Szarkowski’s small, seminal The Photographer and the American Landscape (1963), nineteenth-century American landscape photography—now a boom business and a gilt-edge genre—had little or no exposure. If you wanted to see the work of Timothy O’Sullivan or William Henry Jackson,...