How did U. S. Grant and William Sherman display total war during the overland campaigne and march to the sea

Total war deals with completely destroying an enemy's territory, crops, houses, railroads, etc. In this style of warfare, there are no restrictions as to what can be done.

Both Grant and Sherman used this method. For example, in Sherman's March to the Sea, his troops destroyed 300 miles worth of Confederate railroads, thousands of horses/cattle were taken, and the damage caused was roughly $100 million worth.