Possibly to add the appearance of bulk and/or from binding? There were hundreds of female soldiers, on both sides, that disguised themselves as men, including a woman named Mary Owens Jenkins, a PA 9th Cavalry soldier.
I'm not saying this is Mary - I could not find a photo of her online. Mary Owens supposedly joined the service to be with a man she loved, William Evans. She used the Alias John Evans. William Evans reportedly died and Mary/John stays in Service. Abraham Jenkins, whom she did marry, was also in the 9th PA.The little specks are on my scanner or on the photo glass. The image is very nice, sharp and clear.
A small spot by her face, is the only real condition issue. Rare unusual history gay spy south southern union military photography photograph 1860s soldier picture antique vintage 1800s. The item "Rare & intriguing 1860s photo female civil war soldier dressed as man" is in sale since Friday, November 03, 2017. This item is in the category "Collectibles\Photographic Images\Vintage & Antique (Pre-1940)\Ambrotypes".The seller is "jack_mord" and is located in Woodinville, Washington. This item can be shipped to United States.