In 1955, having ended his high-profile career with "Life" magazine, W. Eugene Smith spent a year in Pittsburgh compiling nearly 16,000 photographs. Only a fragment of the work was ever seen, despite Smith's conviction that it was his greatest set of photographs. Now, in an assemblage of pictures that Smith asserted were the "synthesis of the whole", we see a portrayal not just of Pittsburgh but also of mid-20th-century America by a master photojournalist.