The 1861 United States Army regulations, Article XLII, states that the Quartermaster Department provides the quarters and transportation of the army; storage and transportation for all army supplies; army clothing; camp and garrison equipage; cavalry and artillery horses; fuel; forage; straw; material for bedding and stationery. The Quartermaster Department also handles the incidental expenses of the army such as per diem to extra duty men, postage on public service, the expenses of courts martial, the pursuit and apprehension of deserters, the burials of officers and soldiers, hired escorts, of expresses, interpreters, spies, guides, veterinary surgeons and medicine for horses, supplying posts with water; and generally the proper and authorized expenses for he movements and operations of an army not expressly assigned to any other department.

Thus the duties of the Quartermaster generally fall into several categories. These include the proper care and maintenance of barracks and fixed quarters, army transportation (of men and supplies), provision of forage and straw, provision of paper, writing implements and proper forms, payment of extra expenses such as courts-martial, postage and extra duty, supply of clothing, camp and garrison equipage. The Quartermaster is responsible for reporting the issue of supplies and documenting their use, need for replacement, and the general care of government property. The Quartermaster in the field frequently transports issues items from the Subsistence and Ordinance Departments. In the latter part of the war, the Quartermaster Department assumed responsibility for the burial of troops and the registration of graves.

The Broad responsibilities of the Quartermaster Department can be categorized as falling into one of two categories. The first is staff support and procurement. This function was placed under the command of the Quartermaster General. This aspect of Quartermaster operations involved the purchase of items such as clothing, camp equipage, paper, straw, feed for animals, and horses. This was done by the production of goods under Quartermaster supervision in government arsenals and by purchase from private contractors. This support and procurement function also included providing transport for both troops and supplies to the various military districts. To meet this need the Quartermaster Department both purchased and chartered ships, purchased wagons, contracted with railroads, and even acquired its own rolling stock.

The second category of Quartermaster activity involves field operations. Each functional military unit in the field has at least one officer appointed as Quartermaster. In addition, this officer normally has one or more non commissioned officers who keep records and carry out Quartermaster in carrying out his duties. The Divisional Quartermaster was usually either a Major or Captain. The Brigade Quartermaster was normally either a Captain or a First Lieutenant. The Regimental Quartermaster was either a Second or a First Lieutenant. The Company Quartermaster is a non commissioned officer reporting to the First Sergeant and the Company Commander.

The Quartermaster Department generally transported and issued supplies to Military Districts and from there to the armies in the field. Both the districts and the armies established depots for the collection and subsequent issue of supplies. From the depots supplies flowed down the chain of command from army to corps, from corps to division, from division to brigade, brigade to regiment, and to the companies.

The Quartermaster was responsible for the transportation of goods to the various military units. All quartermaster goods, commissary supplies, and ordinance supplies were transported to the field by the Quartermaster. Commissary supplies were usually delivered to the Subsistence (Commissary) department or officer upon arrival at their destination. The various unit Quartermasters were then responsible for the issue of supplies (except for food) to the troops. Supply and baggage trains were placed under the command of the Quartermaster, subject to orders of the unit commander. Any such train was placed under the command of the senior Quartermaster present. For example, regimental trains were under the command of the brigade or division Quartermaster, depending on the order of march. Among other duties, the Quartermaster was responsible for inspecting baggage trains to insure that they were not overloaded or that individuals did not exceed the appropriate baggage allotment specified by regulations. Quartermasters could, after conferring with the appropriate commander, order excessive baggage to be unloaded.

Quartermasters were responsible for keeping accurate records of government property. Supplies were requested through a requisition form specified in Army Regulations. Different forms were used to requisition fuel, hay, straw, paper, etc. Supplies issued were recorded with a voucher for articles received. Quartermasters also conducted routine inventories of supplies on a regular basis as specified by regulations. Any property used up in service, expended, or lost was accounted for by a Quartermaster. Most of the paperwork for this record keeping was done by NCOs and supervised by an officer. Because of the requirement that enlisted Quartermasters read and write fluently, most of the enlisted quartermasters were senior sergeants.