What was the aim of "total war" as practiced by union generals grant and sherman?

Total war is the practice of putting all your resources into one effort, war. The practice here was to most likely to overwhelm the south into submission, and to help preserve the Union from the threat that was the south. Also it may've been to make that event blow over as quick as possible, as not only man fought man, but father fought son, brother fought brother, it was chaotic. The morals were tearing apart not only America, but the families. 

If u can translate that to english i will surely you!