What does the map illustrate about the Confederate defense?

The map shows how confederate positions were defeated by Union forces and their march began.

Explanation:

Around 29 March and 31 March 1863, General Grant, accompanied by the Union army, began what is known as the "Grant's March," a movement that went down the Mississippi River from Tennessee to Vicksburg. The campaign consisted of several battles and was a major victory for the Union forces as they conquered one of the Confederate Forces ' last controlled areas.

As the map shows, confederate defenses were defeated by the Union forces as they began their march to Vicksburg, crushing the Confederate on all occasions they encountered through the Mississippi river region.