This collection contains material for the 2006 publication Selected Letters of Robert Penn Warren: Triumph and Transition, 1943-1952 (Volume 3), edited by Randy Hendricks, James A. Perkins, and William Bradford Clark. Most of the material is copies of Warren's letters with edits by Perkins. There are also drafts and a page proof of the manuscript, as well as correspondence with the publisher, Louisiana State University Press.

The collection consists of four series: Series I: Copies of Robert Penn Warren Correspondence; Series II: Edited Correspondence Transcriptions, with notes from the editors; Series III: Drafts of Selected Letters of Robert Penn Warren: Triumph and Transition, 1943-1952; and Series IV: Other Papers, which includes correspondence with the publishers. Most of the material dates from between 2004 and 2006. The original Robert Penn Warren correspondence, which is photocopied and included in the collection, dates from 1941 to 1952, though the copies and edits by the publishers date from 2004 to 2006.

For similar collections, see MS.2834: James Perkins' The Cass Mastern Material Papers, 1996-2005, and MS.2637: the David Madden Papers, 1968-2001.