{I'm having problems posting pic's at the moment so that is why I'm posting links}
I think the Alabama militia imo needs some Kepis but the southern units look really good as they are and so do the northern units but I think you should just change it so the "northern" units don't have the cowboy/slouch hat. The Ranger unit I think should be changed to US Regulars Infantry and Cavalry and given Kepis and uniforms with light blue pipping for the Infantry and yellow for the Cavalry. US Regulars were career soldiers and not volunteers like most of the army would have been and it would have shown on the battlefield I can't think of any US rangers in the war the only rangers in the war were Mosby's rangers a southern Cavalry regiment
And here's a link to the Model 1839 forage cap I think it should be used for some of the militia on both sides it was still popular at the time