Complex sentence: At the outbreak of the Civil War, he joined the Confederate States Army and served under Gen. N.B. Forrest and was paroled with him at Gainesville, Alabama, in May 1865.
Split into simpler sentences: At the outbreak of the Civil War joined the Confederate States Army and served under Gen. N.B. Forrest. Paroled with him at Gainesville, Alabama, in May 1865.