This is a portion of a larger photo. The rest of the photo does not give the impression of snow. No snow on the roofs. I believe it must have been a sunny day with sun-light reflecting on the ground. If you'll notice one of the taller buildings in the center of the photo seems to have a rectangular hole in the second story level. This photo matches the photos taken by Russell during May of 1963 at Fredericksburg in the types of buildings and terrain.

"Was there a meeting before the battle of Fredericksberg to allow the citizens, or to warn them, to evacuate?"

I have not heard of one.

David