This dissertation is an edition of the letters exchanged between Charles Peirce and the Open Court Publishing Company (OCP) 1890 to 1913, roughly the last twenty-three years of Peirce’s life. OCP published more of Peirce’s philosophical writings than any other publisher during his lifetime, and played a critical role in what little recognition and financial income he received during these difficult, yet philosophically rich, years. This correspondence is the basis for much of what is known surrounding Peirce’s publications in The Monist and The Open Court, and is referenced often in Peirce editions dealing with his later work. Peirce’s OCP correspondents included Paul Carus, editor; Edward C. Hegeler, founder and owner; Thomas J. McCormack, assistant editor and translator; Francis C. Russell, Chicago attorney and OCP editorial contractor; and various other OCP editors and staff members. Also included in this edition (Appendix) are enclosures and other material related to the letters, with some exclusions noted in the text. Not included are letters exchanged within the OCP organization that make reference to Peirce. Significant portions of these letters are quoted or referenced in editorial notes, but their entirety is not necessary for a full account of the Peirce–OCP relationship, and for now falls out of the scope of this edition. The objective of this edition is to provide for the first time a complete and accurate text of this oft-cited correspondence, with textual apparatus and contextual annotation. The edition is intended for Peirce readers, but is also a valuable reference for those interested in the history of OCP and, more generally, of Progressive Era American philosophy. / 2024-03-31T00:00:00Z