To get into the Bettmann Archive, about 90 minutes north of Pittsburgh, you need more than a library card. You need the proper credentials to get past the armed guards at the door. You need to be gloved and swaddled in several layers to deal with the cold. And you need to be OK with claustrophobic conditions, since the trip requires being shuttled hundreds of feet underground. If you meet all those conditions, you might get a glimpse of Getty Images’ hidden trove of photographic history. Eighty-five years ago, 32-year-old…
