Many may not realize it, but in some instances women would follow troops around from place to place as they marched. They would give "comfort" to the men during downtime. The term "hooker" comes form Union general Joseph Hooker, who was well-known for keeping women-of-the-night near. The Union soldiers had about 200,000 confirmed cases of syphilis and gonorrhea. Likely, many deaths came from this. For the men who were not lucky enough to have a travelling sex-for-sale entourage, some would carry pictures of naked women that could be bought in secrecy. The best place to keep such "forbidden fruit" was inside their Bible, of all places!
I am not surprised in the least, actually. Depictions of humans, eh-hem, engaging in relations have been found in the earliest dawn of human civilizations. It was quite common, for example, in ancient Rome. Many civilizations had paintings, statutes, limericks and the like that has about such thing. In fact, the second oldest joke in recorded history (circa 1600 BC) was quite possibly a sex joke: "How do you entertain a bored pharaoh? You sail a boatload of young women dressed only in fishing nets down the Nile and urge the pharaoh to go catch a fish."1 So, Billy Yank or Johnny Reb sneaking some naughty daguerreotypes isn't too much of a shocker.
The term is "campfollowers". And the Europeans armies are known to have organized them. The French of Napoleans day called them "La Vandierers" (or something like that) and put them in a form of uniform. The British and American armies put the wives of some soldiers "on establishment" as "laundresses" and the like. But this is not to say wives and laundresses were comfortwomen. As regarding the ACW, I know the Union army permitted SUTTLERs to accompany the troops in movement and especially in garrison. Suttlers were permitted to sell certain items legally to troops, and were often suspected of 'blackmarket' traffic.
When I think of physical sexual depictions, I always think of the Spaniards destroying the art and scrolls and religious material and objects of the Mayans and Aztecs, as they considered them lewd. People were really into themselves back then. I cannot imagine being so pompous that I would destroy another cultures' art and religious items. My point being that sex was a lot more open in some cultures than others. Obviously eastern European and Western cultures kept it on the down-low.
There has been indeed many times in which on culture has defaced the religious articles, arts, objects, etc. of another. It is a pretty common theme in ancient history and lingers on into the modern era. Some of it was just thuggery, but much of it was inspired by the notion that they were doing the will of God/gods.
I love that this is a fact of history that people don't really talk about, and you have now just pointed out. I knew that prostitution is the longest lasting profession on Earth, so that part doesn't surprise me. I wonder where they got their pornography from, since it took forever to take a picture during that time. I wonder what type of women would pose for that long in the nude. Then again, they did it for artists all the time, so it is comprehensible. Wow, now I can't stop thinking about the fact that they hid their dirties in the Bible.
"I wonder what type of woman would pose that long in the nude"? One of the sisters of Napoleon, Emperor of France, for one. He had many, I forget her name. But when the angry emperor ask how she could do it, she sweetly and glibly replied "there was a fire in the studio."