Complex sentence: Under an act of Congress dated 3 March 1815 the Regular Army was drastically reduced, eight infantry regiments, one rifle regiment and artillery were formed from the remains of the 46 and 4 existing regiments, the cavalry was eliminated.
Split into simpler sentences: Under an act of Congress dated 3 March 1815 the Regular Army was drastically reduced. Eight infantry regiments, one rifle regiment and artillery were formed from the remains of the 46 and 4 existing regiments, and the cavalry was eliminated.