CAM,

I guess I already answered a similar post you made about this unit a few months ago. The comments I made then appear below:

I unearthed some information on this battery while researching my book "That Body of Brave Men: The U.S. Regular Infantry and the Civil War in the West." One of the regiments featured in my book, the 18th U.S. Infantry, was assigned to Col. Robert McCook's brigade in the Army of the Ohio during 1861-1862, and I/4th U.S. Artillery was also assigned to McCook's brigade.

I found one original manuscript source written by a member of this battery. Pvt. Oscar P. Heath wrote a short unpublished essay entitled "The Battle of Chickamauga as I saw It," a copy of which is in the 4th U.S. Artillery File at the Chickamauga-Chattanooga National Military Park Libary.

I don't have any 1865 information on this battery, but I hope this helps!

Mark