The major river that split the Confederacy into two parts was the Mississippi River. During the American Civil War, control of the Mississippi River was crucial for both the Union and the Confederacy.
The Union’s successful campaign to gain control of the river effectively divided the Confederacy geographically and logistically. This occurred primarily through the Vicksburg campaign, culminating in the Siege of Vicksburg in 1863. After the Union victory at Vicksburg, the Confederacy was cut in half, which disrupted supply lines and made it significantly more challenging for the southern states to support each other in their war efforts.
The strategic importance of the Mississippi River was recognized by leaders on both sides, highlighting its role as a vital artery for trade and movement of troops. By controlling the river, the Union not only diminished the Confederate’s resources but also bolstered their own ability to transport supplies and reinforcements.