Complex sentence: Clark enlisted in the 1st New Jersey Volunteer Infantry in April 1861, and became a sergeant in Company F. When the regiment's three month enlistment ended, Clark was involved in raising 2nd Battery "B" New Jersey Volunteer Light Artillery.
Split into simpler sentences: Clark enlisted in the 1st New Jersey Volunteer Infantry in April 1861. He became a sergeant in Company F. When the regiment's three months enlistment ended, Clark was involved in raising 2nd Battery "B" New Jersey Volunteer Light Artillery.