Complex sentence: A third variation, known as'Delta' from an alleged use in the Mekong Delta area of South Vietnam was issued in the early 1970s, so that by the end of the Vietnam War American troops wearing camouflage combat dress had become the norm.
Split into simpler sentences: A third variation, known as'Delta' from an alleged use in the Mekong Delta area of South Vietnam was issued in the early 1970s. By the end of the Vietnam War, American troops wearing camouflage combat dress had become the norm.