Style Chart for Garments

When you are shopping for vintage clothing, or trying to read patterns old or new, these charts will give you an idea of sleeve,and collar variations. (photos from Vogue Sewing)
Pointed flat collars are most appropriate for Civil War dresses. A smaller scale Peter Pan collar, very narrow, would also be acceptable. Civilian men's shirts might have a Mandarin-type collar, but much narrower.
Bishop and Bell sleeves are period correct - the dropped armscye, with fullness at the elbow are the key elements.