This diary was referred to in “Uncommon Soldiers”, the Harvey Reid letters, and has turned up on Amazon in Kindle format from Scott A. Irons, a descendant. https://www.amazon.com/Flag-Free-Civil-Selected-Speeches-ebook/dp/B01NAL0D3M/ref=sr_1_9?s=books&ie=UTF8&qid=1545176453&sr=1-9&keywords=flag+of+the+free
The Wisconsin Historical Society has the diary in collection named “Charles H. Dickinson journal”, with call number “Wis Mss 35S”. Contact them at firstname.lastname@example.org.
Mr. Dickinson was a Sergeant in the 22nd Wisconsin in Coburn’s brigade, the 2nd in Butterfield’s division. Coburn followed Ward in the assault and was driven left. Dickinson’s account is the first I have seen that mentions facing the barrier of sharpened felled trees that is seen in Walker’s painting. He added having to work to the right to get around not just those but telegraph wires tied across trees and brush! Sharpshooters were busy on those struggling with the barriers. Dickinson helped one wounded get back to where they started and where those they had to step over were still lying down.
Then, he has interesting accounts of Peach Tree Creek and the Battle of Averysboro [his spelling]. The latter matches Halstead’s story of Private Totton and adds the detail that a lucky Union cannon shot silenced a Rebel cannon on that end of the field by exploding their their caisson full of shells, killing all six horses and several soldiers, which caused quite a commotion in the Rebel line just as the 1st Brigade, then under Col. Case, was starting their attack. So the Halstead-Totton rout of the unsupported Rebel flank was a helped by yet another bit of fortune.