This is a microcosm of the danger facing American archives. Because almost nothing is catalogued at the item-level, most of the unique material housed in these most important of repositories is particularly vulnerable to theft. When someone like Breithaupt steals a book, even a very old book, there is a catalog record that tells us it is missing—and likely some kind of duplicate copy somewhere else in the world. But when he steals a letter from Flannery O’Connor to John Crowe Ransom—unless that letter has been photocopied by another person—it basically ceases to exist. Not only do we not have the information in it, but we don’t even know that we don’t have the information in it.

Source: The Unseen Theft of America’s Literary History ‹ Literary Hub