Complex sentence: One, Colonel Freeman Norvell, was a Marine Officer who fought at the Battle of Chapultepec in September 1847, and at the Battle of Gettysburg in 1863 and his younger brother Lt. Dallas Norvell served on the staff of General George Custer.
Split into simpler sentences: One, Colonel Freeman Norvell, was a Marine Officer who fought at the Battle of Chapultepec in September 1847, and at the Battle of Gettysburg in 1863. Freeman's younger brother Lt. Dallas Norvell served on the staff of General George Custer.