VERY enlightening as well as entertaining. It's packed with pictures. This lady took a huge sample of Civil War era photos, and categorized "who wore what" by age and economic status. Some results are not at all what you'd think. She points out that most pictures are selected to illustrate a certain point, and few "ordinary" pictures are published. She focuses on ordinary and average instead, because that's what we usually want to go for in our impressions.
My biggest surprise was the white collars, which I never really noticed, but sure enough the vast majority of ladies wore them with their dresses back at that time.