Controlling the River: The Mississippi River was a vital transportation route for the Confederacy. It provided access to the Gulf of Mexico and allowed for the movement of troops, supplies, and trade. By controlling the river, the Union could disrupt Confederate logistics and cut off their access to resources.
Splitting the Confederacy: The Mississippi River also served as a dividing line between the eastern and western Confederate states. By capturing the river, the Union could split the Confederacy in two and make it more difficult for them to coordinate their efforts. This would weaken the Confederate war effort and make it easier for the Union to achieve victory.
Economic Impact: The Mississippi River was also an important economic artery for the Confederacy. It was used to transport cotton and other agricultural products to market. By capturing the river, the Union could damage the Confederate economy and further weaken their ability to fight the war.
Psychological Effect: Capturing the Mississippi River would also have a significant psychological impact on both the Union and the Confederacy. It would boost the morale of the Union troops and demonstrate the North's determination to win the war. Conversely, it would demoralize the Confederate troops and make them question their chances of victory.
In conclusion, the North believed that capturing the Mississippi River was worth the effort due to its strategic importance in terms of transportation, logistics, economics, and psychological impact on both sides of the conflict.