The south had won defensive battles in the east, but lost in the west. Tennessee was lost, along with the south’s major source of pork (protein). Vicksburg chopped off Texas (beef), Arkansas, and took most of Mississippi. After defeat at Vicksburg, US forces would turn east toward Chattanooga and Atlanta’s capture would assure the reelection of Lincoln.
The south was losing the war, but just losing more slowly in the east due to the decision to suck more rebel units from the west to the east.
And as the south slowly lost in the east, US Naval supremacy on the high seas took increasing effect.
It did take awhile for the incompetent union to kill of the republic. It should have been over in a month or two if you compare the two sides militarily/industrially.