The above strap is that of a staff major with the metallic letters "QM" added to indicate a Quartermaster. Similar straps with other letters were used by other staff departments, but the majority of staff officers wore straps with a plain dark blue field that did not distinguish their particular department. The use of letters was never recognized by the official uniform regulations of the Union Army. The officer who originally wore this strap was likely a divisional quartermaster; however, some of the larger depots later in the war were supervised by officers with field grade rank.
The efficiency and effectiveness of the Quartermaster Department in providing the services of supply during the Civil War allowed the Union army to project force into the heart of the Confederacy. Quartermasters were often castigated for their failures, but rarely recognized for their more frequent successes. There were quartermaster officers functioning at every tactical level of organization within the army from the regiment upwards and additional officers assigned to regional depots. These officers were subject to orders from their superiors within the department and also from the line (combat) unit's commander. The Quartermaster's Department was directed by Brigadier General Montgomery Meigs. The organization system evolved during the war and in its final form was as follows:
|Lieutenant Colonel||Army Corps||Chief Quartermaster|
|First Lieutenant||Regiment||Regimental Quartermaster|