Many of the prints displayed on the walls of the main gallery of Firestone Library during the exhibition “Versailles on Paper” belong to a vast collection known as the Cabinet du Roi: copperplate engravings produced and distributed by order of Louis XIV. They came to Princeton in 1886, when the Bibliothèque Nationale sent four large boxes of books and prints to the College of New Jersey in exchange for more than three hundred volumes on the American Civil War donated by John Shaw Pierson (1822–1908), Class of 1840. The discovery of this curious transaction during the preparation of the exhibition raised a number of questions that the present essay attempts to answer: What led Pierson to act as foreign agent on behalf of his alma mater, and how did he approach the Bibliothèque Nationale? Why was the Cabinet du Roi included in the exchange, and how were these prints received and used at Princeton? While John S. Pierson's role in the early development of Princeton's historical collections is well known, the 1886 exchange with the Bibliothèque Nationale (and other European libraries) has been all but forgotten. It deserves to be brought back to light and calls for a broader reassessment of Pierson's purpose as a collector and benefactor.