The Confederacy covered a vast territory, stretching from Virginia in the east to Texas in the west, and from Kentucky and Tennessee in the north to Florida and the Gulf of Mexico in the south. This made it difficult for the Union to control and occupy the entire region, as it required a large number of troops and supplies to be spread out over a wide area. The Confederacy also had the advantage of being able to use its interior lines of communication to move troops and supplies quickly between different fronts, while the Union had to rely on longer and more vulnerable supply lines. This made it difficult for the Union to coordinate its operations and maintain a sustained offensive against the Confederacy.
In addition, the vastness of the Confederacy meant that the Union had to occupy and control a large number of cities, towns, and other strategic points in order to effectively defeat the Confederacy. This required a significant commitment of troops and resources, and it also made it difficult for the Union to maintain control over the occupied territories and prevent the Confederacy from launching guerrilla attacks or other forms of resistance.