A large part of what I do while researching historical documents or images is read between the lines, or draw logical inferences. Making historical information feel immediate and alive to readers means feeling my way into the material. This photograph from the Library of Congress website collection of Civil War photographs provides a good illustration. (Some details may be hard to see on your screen, so just bear with me. ) At first glance this photograph seems rather mute. Most kids seldom look at black and white images, and this picture might say nothing to a contemporary student. But with a little practice we can infer a great deal about the circumstances of this photograph, and paint a more colorful picture.
We can infer, to begin with, that the time of year is not winter -- we see leaves on the trees. Okay. Can we pin it down further? Yes, I think so. You notice how dusty the road looks -- the wheel tracks are deep but dry. I don't think it has rained for several weeks. This suggests late summer, right? And the shadows are crisp and sharp, so it's a bright sunny day, and probably hot. All at once I can bring all of my experience of "hot bright late summer day" to this photograph, and I can hear the cicadas buzzing in the trees, and see the swallows swooping for mosquitoes over the creek, and smell the damp stones in the arches of the bridge. I don't need direct, documentary evidence of the cicadas or the mosquitoes or the swallows; indirect evidence abounds. In doing historical research the writer (of fiction as well as nonfiction) can safely extrapolate a great deal from available evidence.