Complex sentence: At the beginning of the Civil War, Kay enlisted in the Confederate military's Richland Rifles serving as an engineer, and served as a non-commissioned officer in the campaign to capture Fort Sumter in April 1861.
Split into simpler sentences: At the beginning of the Civil War, Kay enlisted in the Confederate military's Richland Rifles, serving as an engineer. He served as a non-commissioned officer during the campaign to capture Fort Sumter in April 1861.