Call me crazy and uneducated on the matters of Texas Rangers, but that hat reminds me of them so much and now the whole image evokes an idea of rough and ready Confederate troops, used to living off the land and ready to outfight the better equipped Northern forces.
you're quite right actually. during the early parts of the civil war (the real one) the south was doing pretty well due to their knowledge of the terrain and that they were well supplied on their own turf. it wasn't until the north was able to divert enough of its resources to the front lines did they start to get the edge
so with that in mind the rangers were an ideal choice due to their long range and fast maneuverability coupled with their outdoors-man skills. while design wise i try to make confederates look like they're ready to camp out at a moments notice.
plus back in the days of the first world war rangers did wear hats like that.