I believe, generally, there is no remission of sin without the shedding of blood, and the sin of rebellion is no exception. True here as very often, the blood of the innocent must mingle their blood with the guilty.
Bowler was an undergraduate student at Oberlin College in Oberlin, Ohio on the outbreak of the U.S. Civil War. A company of soldiers was raised from Oberlin College (led by three professors), which Bowler joined on April 17, 1861. The unit became the Seventh Regiment Ohio Volunteer Infantry, Company C. Bowler was promoted to sergeant. Less than a year after writing the above letter to his brother Bowler was killed at the Battle of Cedar Mountain in Virginia on August 9, 1862.
Source: Itinerary of the Seventh Ohio Volunteer Infantry, 1861-1864, edited and compiled by Lawrence Wilson, First Sergeant Company D (New York: The Neale Publishing Company, 1907) (pg. 420).