Have traded notes with Stephen Sears who pointed out to me that May McClellan's extracts of the unseen Civil War letters are in the McClellan Papers (LoC and microfilm) and therefore retrievable. He says he used these plus GBM's notes in the notebook to reconstruct the material in his book, The Civil War Correspondence... He disavows any reliance on W.C. Prime's combined version of May's material and the notebook.
This would mandate a redrawing of this chart as follows: a line should extend from the box "May McClellan's Extracts" down to Stephen Sears. Sears said he did not rely on Prime for anything, so the line from Prime to Sears should be removed.
We discussed my accusation that he had struck a line about Kentuck from his renderings of the material. I went back to my notes and saw that what he had struck was merely a footnote from Prime explaining the reference to Kentuck. I apologized for the error.
Sears has worked hard with source materials to try to provide an authoritative work. I told him that the result is not a primary source. He told me that he thinks most ACW authors would agree with him that these are letters. Undoubtedly, they would.
I would like to change that someday. That does not require that he or his work on this project be disparaged, which I shall keep in mind.