Jean,
Thank you so much for continuing to dig out this information.
Maybe there is something to the story. If so, I'd sure like to know and can connect some of the stories of my g-g-grandfather William's war experiences. I did find that his unit arrested a southern sympathizer from LaPlata the last week of October and on the way to the prison in Macon, someone shot and killed the suspect. The first week in November, his unit was sent to Howard county to give a military presence at polling stations for the presidential election of 1864. They were also involved or associated with the burning of property belonging to known confederates. Maybe there was a hanging in his experiences too?

I'm sure there are any similar occurances in every county & state involved in the war that happened that nobody will ever know.
Along with stories written and told that never really happened.

The book you are asking about is called "The History of Randolph and Macon Counties Missouri" published in 1884.
It is in the digital collection State Archives. In the Macon section, chapter XII Different Wars, page 865. is the controversial entry supposedly taken from "the true democrat" describing the hanging along with the mysterious Major McKay.

My appreciation to all you and others have done for this is so great, that I am energized to continue searching. Unfortunately, I am fairly unskilled in the research methods and resources.

If you find anything else of significance, please let me know.
thanks, Don