The Personal correspondence series includes correspondence between William Pahlmann and friends, business associates, and various clients throughout the United States, Asia, Europe, and Latin America. Pahlmann and his correspondents discussed interior decoration, specific decorating jobs, gossip about other friends and associates, and business transactions. Many of the items in this series concern Pahlmann's numerous excursions throughout North America, Asia, and Europe. Materials that deal with Pahlmann's travels include itineraries, correspondence about the excursion, information on airline and hotel reservations, and various mementos.

Items in the Personal correspondence series provide a glimpse of Pahlmann's extensive social and professional network as well as the many places he traveled for business and pleasure. Pahlmann's correspondence helps demonstrate the extent to which his business depended on his numerous contacts throughout the world. These items also illustrate some of Pahlmann's methods for orchestrating major projects and events in remote locations, such as Hong Kong and Europe.