Civil War winters were both trying and monotonous for both armies. Muddy roads and harsh weather all but stopped active operations. Disease ran rampant, killing more men than battles. But winter still allowed soldiers the opportunity to band, have a little bit of fun, and enjoy a permanent camp. Basically all one had to do in order to survive was keep warm and busy.
When they were on the move and in warmer weather, soldiers often slept in canvas tents, or they slept without cover under the stars. In the winter that all changed, as large camps were established with substantial shelter. Winter huts were built by the armies out of whatever materials they had access to, trees, mud, leaves, and soldiers' canvases. These huts usually included a chimney which kept the small space warm, but some were more effectively built than others.
The camps were set up much like small villages, complete with crisscrossing lanes called company streets. There were also churches and sutters' shops. Camps may have seemed cozy, but what they lacked were the appropriate systems to provide clean water and clear away waste. Additionally, food was scarce. Disease and death abounded, and spread easily.
However bad the weather was, boredom was he ever present problem. Both commanders and soldiers alike tried to establish both work and activities to break the monotony. Drilling, camp upkeep, religious services, letter writing, card games, storytelling and even an occasional snowball fight were all part of camp life.
Despite all the best efforts of their offices, many soldiers strayed to less desirable activities. It was a bad thing for an army to remain in one place too long, the men would become discontent and unhappy, and having no diversion or pastime they'd take to playing poker or chuck-a-luck.
When spring arrived, the soldiers gathered their belongings, including their canvases, and marched away. The camps remained and in some cases soldiers saw their old camps again the next year.