If you think about the scope and effect of Sherman’s March to the Sea, you’d imagine that the Confederate army would’ve tried to stop it in its tracks, right? Now, to be entirely fair, they did make an attempt, but the truth still stands that the Union army was, to a large degree, basically unopposed for much of the operation.
On one hand, that had to do with some pretty smart planning on William T. Sherman’s part. He kept his cards close to his chest, even going so far as to sever telegraph lines just to make sure it was impossible for information to get out, and keeping many of the details of his plans private, even from his superior officers and the men under his control. Then, when he did let some information loose, it was actually misinformation. Confederate generals thought they had his plan figured out, only to dispatch forces toward cities that Sherman actually had to interest in. That actually left very few forces available to even attempt to stop him — a small cavalry force caused some headaches, and a handful of battles erupted during the March, but they were generally all relatively small skirmishes. Not nearly enough to actually stop the March.
Really, that all sort of culminated in Sherman’s arrival in Savannah. The Confederate army was quick to flee at Sherman’s presence (or had already abandoned the city, depending on whose account you’re reading).