Michael Thurwachter/Thuerwaechter from Fond du Lac was killed in action at Chancellorsville, VA on May 2, 1863 which seems to match your date. He was from the 26th Reg Wisconsin Infantry, Co E also called the "Fond du Lac Turners" He was a Corporal. He enlisted on 8/15/1862.

This information from Soldiers and Sailors website, also from http://www.russscott.com/~rscott/26thwis/26pghist.htm and ancestry.

For genealogic information, you might request his military records.

Bonnie