Control of the Mississippi River was critically important because it served as the most vital transportation and supply route in the United States, especially during the Civil War. Both the Union and the Confederacy relied heavily on the river to transport goods, soldiers, and military supplies. Controlling the river allowed the Union to split the Confederacy in two, cutting off essential supplies and communication between its eastern and western parts, which weakened the Confederate war effort significantly. This strategic value made the river a key objective for both sides in the war, with major battles fought to secure control over key points like New Orleans, Vicksburg, and Memphis. The Mississippi River was also essential for the shipment of agricultural products from the Midwest to markets in the eastern U.S. and abroad, making it economically crucial beyond its military value. The Union's Anaconda Plan aimed to blockade Southern ports and advance down the river to effectively constrict the Confederacy, much like an anaconda squeezing its prey. Ultimately, the Union’s control of the river gave it a major advantage in winning the war by disrupting the Southern states' ability to function as a unified whole. In summary, controlling the Mississippi River was vital for transportation, military strategy, economic sustenance, and dividing the Confederacy to secure Union victory in the Civil War.