“I have been writing fiction rather passionately, singlemindedly, perhaps insatiably, since I was fifteen or so,” J. D. Salinger wrote in 1982. “I positively rejoice to imagine that, sooner or later, the finished product safely goes to the ideal reader, alive or dead or yet unborn, male or female or possibly neither.” This document is now included in an exhibition that allows the author’s many ideal readers to see further into his life. Organized by Salinger’s son and widow, and coinciding with the centennial of the author’s birth, the free exhibition includes more than 200 items—from the original typescript of The Catcher in the Rye to correspondence with friends, including Ernest Hemingway. —J.V.