The Battle of Antietam is also known as Sharpsburg. Bull Run is also called Manassas. Shiloh is also Pittsburg Landing. Some of these may be familiar to you, some of them may sound weird. But there is a reason for it, and it's mainly because of the Soldiers who fought the War Between the States.
History class is difficult enough without having to remember two names for each event. If you grew up around Murfreesboro, chances are good that's how you (or the older members of your family) refer to the battle. You'd cock your head in bewilderment when someone calls it, "Stone's River." Well sorry, Tennessean; there were two American sides to this war and your side lost.
There is a system in place for this duopoly. And it's not like calling Janet Jackson "Miss Jackson" just because you're nasty.
Have some respect for the Commander in Chief of Rhythm Nation.
When the battles of the 'War of Southern Independence" were fought, the troops gave them names after what stood out most. The bulk of Union troops, being city dwellers and townspeople, remarked on the natural features of a battlefield. Confederates, by and large from rural areas, remembered the manufactured, populated, or otherwise man-made features of the area. So, where Northerners saw Bull Run, a tributary to the Occoquan River, Southerners thought about the local railroad station nearby in Manassas, Virginia.
It was also convenient to their final resting places.
So, now the battle had two names.
Many battles are well-known by just one name, however. And for the ones that do have two names, one is typically more known than the other. The reason for that is simple, too: history is written by the victors, and the War of the Rebellion is no different. With a few notable exceptions, the battles were named by the victor.
The National Park Service is a little more conciliatory in this regard. When memorializing major battles of the War of Secession that were fought in the South, the NPS will sometimes use the Southern name of the battle, regardless of the victor.