He died in about 1860 in your question and the WikiTree profile has it 1861. If he died in 1860, it was before the Civil War started, but if it was in 1861, he could have been killed in combat early in the war.
I'm grasping a little so far. In looking at familysearch.org , I did not find anything significant. There is a good write up about his daughter's husband at Find A Grave, but William Lewis's burial remains elusive at this point.