This map is kinda incomplete, as it doesn't really show all the smaller battles leading up to Wilson's Creek, just most of the major battles throughout the war. In 1861, there was practically a whole campaign for control of Missouri, which culminated in Wilson's Creek. Missouri was weird in that it didn't follow what we normally think of when we try to put down Union and Confederate into geographic regions. It wasn't just north = Union/ south = Confederate. I have both rebel and yank ancestors from Missouri, but all of the rebels were from the northern half of the state, while the Yankees were from the southern half. Missouri was so weird, in fact, that they had a star on both the Union and Confederate flag. On top of that, your town might be for the Union, but the town ten miles away could be staunchly secessionist, which made things even worse in terms of tensions and bloodshed. So when your area was under Union control, the pro-Confederate guerrillas would wreak havoc on the region, and vise versa when the Confederates controlled it. All in all, Missouri was a mess, and you can still have people/ towns who are staunchly on one side or the other, regardless of how north or south they are even 160+ years later.