Complex sentence: The regiment thus formed was intended be commanded by Colonel Burleson, temporarily, but Lieutenant Colonel Charles H. Matlock, recently returned to Arkansas from the 2nd Arkansas Mounted Rifles, was ordered to report to Colonel Burleson for duty.
Split into simpler sentences: The regiment thus formed was intended be commanded by Col Burleson, temporarily, but Lieut. Col. Charles H. Matlock, recently returned to Arkansas from the 2nd Arkansas Mounted Rifles, was ordered to report to Col Burleson for duty.