Although this thread is a couple of years old, I thought I would comment. After several years of searching, last year I was finally able to track down my mother's grandfather with conclusive evidence he was the correct person. It turned out, Pvt Paul Ellsworth of Company B, 5th Michigan Cavalry is my great grandfather. Also located his grave in the Graceland Cemetery in Chicago. There is no headstone or marker for this veteran. I have submitted and application to the VA to have one installed.
Since this veteran is a new found ancestor, I am still in the process of finding additional sources to learn more about the service of the 5th Cavalry. Internet searches have been made and service records and pension application have been obtained. So far, "Under Custer's Command" by Avery, "Glorious War" by Hatch, "Personal Recollections" by Kidd have been read. According to service records, Paul Ellsworth was never wounded or absent due to illness. He absent in Dismounted Camp for the Muster of Sept/Oct 1863 and again after his horse was killed at Hawe's Shop. Recommendations for further reading to learn about the service of the 5th Michigan Cavalry would be much appreciated.