“The hard core of either army was the infantry company. Its 65-100 privates formed a small workable unit. Because it was raised in a single locale, the company had all the atmosphere and appearance of a large family. ”
James I. Robertson, Jr., Soldiers Blue and Gray: p. 20.
When not engaged in skirmishing, which was rare during the Civil War, some companies found work to do like repairing bridges like this one. This kind of hard work was typically preferred to the monotonous life inside the camp.