The desk above was one of the nerve centers of the Union Army. From here the officers would write their orders to their men, read the correspondence from men above and below their ranks and basically conduct the war.  These simple boxes would be carried on a wagon and placed on a table when the unit stopped for the night and the commander was ready to work until all hours.

When the Civil War started the entire United State Army was about 15,000 men, most of which were posted out west. Of those were about 1,000 officers. Out of those about 140 would actually become generals during the course of the war. These officers were considered “regular army” and  often found themselves in conflict with another group of officers.

When President Lincoln put out his call for troops from the States in 1861 the states that remained in the Union called up their militia units and put them at he disposal of the Federal government.  Officers at the regimental level and above were appointed by the governor. These men and officers of the militia were considered separate from the regular army and carried the designation “volunteers”.

Interestingly enough some officers would actually hold two ranks. One if the regular US Army and one in the Volunteer Army. This was due to the use of the “brevet” system, basically a temporary or honorary promotion to a superior rank.  For example, you may be a captain of a regular regiment, but for a specific campaign and due to good service you are “breveted” to colonel of volunteers so that you could command more men. The regular army rank is always considered the superior of the two.

Interesting enough a number of Union officers were foreign nationals that came to fight in the war and even several Native Americans joined the officer corps. So when you look at that desk above you never know who may have sat there all you can say for sure is that the army was led by a wide variety of men from every walk of life,