I read the book Three Years With Grant as part of my study of war correspondents sent to follow troops during the US civil war. The passage on the campaign at Vicksburg is amazing how Cadwallader saved Grants life, and after that incident was allowed to set up his camp in areas reserved for staff officers. This was unprecedented given the low regard for newspaper reporters often arrested and treated as spies by federal officers during that conflict. Cadwallader even carried orders from Grant to field commanders at times when his staff were busy. These and other facts offer convincing evidence if not proof that this humble civilian did enable the course of the war by saving the general from certain death.
This is a great story that is never told but certainly should be.
Doug Overton