Cameras were invented in 1826 so there should have been plenty of time to make that happen, and if you think people would just be "to scared" to do it at the battle of bull run congressmen took their wives and kids up on the local heights and picnic and called the union boys cowards as they retreated through their picnic.
Okay, so you have no idea how cameras work, especially cameras back then.
You see, when you press the button and hear the “snap” around, there’s this thing called a shutter that closes. The shutter has to process the image with light in order to save the image.
While this happens almost instantly today, Back in the 1800’s, this process could take anywhere from 5-30 seconds to complete. Even longer if you wanted a high quality photos. Ever wonder why no one smiles in old photos? It’s because they had to hold their pose for a good amount of time, it would hurt to be smiling, and if someone broke the pose, the entire photo would be ruined and they’d have to do it all again. There’s plenty of jokes and parodies of people sitting in still frames for long amounts of time to get a perfect photo for this very reason.
Now try and have that delicate process done while people are running around a battle field with bullets and smoke erupting everywhere. Any photo taken during the actual battle would have been an unusable mess.
As for why the photos that do exist look clean? The film didn’t capture a whole lot of detail, which is why everyone looks like they have a modern day smear filter. On top of that, anyone who would be posing for a photo would have cleaned up to the best of their ability. You couldn’t take a candid shot back then, it was a lengthy process and anyone who was photographed was well aware and given the time to be photo ready.
none of this is hard to find knowledge, in fact this was stuff I was taught in grade school.
