Complex sentence: The 3rd Infantry Division was sent to this port on March 7,1943, coming under the command of Major General Lucian Truscott, who took them through rigorous training at Arzew, Algeria, for an amphibious landing at Sicily.
Split into simpler sentences: The 3rd Infantry Division was sent to this port on March 7,1943, and came under the command of Major General Lucian Truscott. The major general took them through rigorous training at Arzew, Algeria for an amphibious landing at Sicily.