As early as the 1930s, Goodrich was recognized by his peers as the preeminent authority on Thomas Eakins. Owners of possible works by Thomas Eakins were referred to him or sought out his expertise themselves in order to establish authenticity of the object. Up until the end of his life, Goodrich remained committed to examining works as they surfaced, taking the steps necessary to make a final decision. In some cases, a photograph or a visual description of the object and its provenance would be sufficient to make a determination, and in other cases he would visit the actual object and make notes and sketches. It is of interest to note that some of the objects reappeared in the hands of new owners again seeking advice on authenticity, thus attesting to the enduring importance of these files in preserving Eakins's true oeuvre.
The bulk of this series consists of correspondence with owners of possible works by Thomas Eakins's, often accompanied by photographic material. Also included are related notes and sketches by Goodrich.