As the New York Public Library entered the post-war era in the late 1940s, its operations fell under the zealous scrutiny of self-styled ‘redhunters’ intent upon rooting out library materials and staffers deemed un-American and politically subversive. The high point of attacks upon the New York Public Library came during the years 1947-1954, a period that witnessed the Soviet atomic bomb, the Berlin airlift, and the Korean War. This article charts the narrow and carefully wrought trail blazed by the library’s leadership during that period. Through a reading of materials in the library archives, we see how political pressures were perceived and handled by library management and staff. We witness remarkable examples of brave defense of intellectual freedom alongside episodes of prudent equivocation. At the heart of the library’s situation stood the contradictions between the principled commitments of individual library leaders and the practical political considerations underlying the library’s viability. As a general rule, the New York Public Library did not hesitate to acquire materials considered subversive by pressure groups, but the library frequently struck a course that sought to avoid controversy when possible.