At the beginning of the war the state of Illinois did not have regulations to cover the uniform dress of its troops except that the officers of regiments should wear uniforms similar to that of the US Army officers. The state hoped the US government would supply its volunteers, this didn't happen. The first infantry regiments were issued gray shirts, blue kepis and red blankets worn over their shoulders horseshoe style very much like the first regiments from Rhode Island under the command of Ambrose Burnside. In May 1861 complete uniforms were ordered from New York. The uniforms included jackets and pants made of coarse gray cloth and a blue zouave cap. The uniforms were made of poor quality material and wore out very quickly. Also in May of 1861, ten more infantry regiments were called for and these wore uniforms provided by their hometowns. In June of 1861 Illinois again made a purchase of uniforms so that each member could be issued a blue or gray round jacket and pants of the US Army pattern, two shirts, two pairs of drawers, two pairs of socks, and one pair of shoes. Most of these uniforms were of gray color due to the shortage of blue wool. In September of 1862 Illinois sent the US Quartermaster the equipment that it had in storage for its troops. The following is what was inventoried by the state for the Federal Authorities. 59,172 caps, 3,432 havelocks, 25,044 dress hats, 19,046 dress coats, 64,412 jackets, 11,072 fatigue blouses, 112,287 pairs of pants, 21,878 pairs of boots, 93,148 pairs of shoes, 72,866 greatcoats, 95,967 blankets 20,367 rubber blankets, 35,223 knapsacks, 45,925 haversacks, 54,740 canteens. No buttons, cap badges, or belt plates were issued with the Seal of the State of Illinois on them.
We will start with one of the most recognized coats of the Federal Army the M-1858 US Enlisted Shell Coat. This waist length jacket was worn by many Federal Artillery and Cavalry units. The picture below is of a Quartermaster Sergeant in full dress for the Light Artillery. The M-1858 jacket has 12 small brass US Eagle buttons on the front and four on the collar. The jacket also has two bolsters in back to support a belt. The figure below is wearing the standard issue sky blue enlisted man's pants. On his head is a M-1861 dress shako and he is carrying a M-1840 Light Artillery Saber. You will also notice the stripes between the figures elbow and shoulder. These are called nco chevrons. These are rank distinction for Noncommissioned officers.
The Fatigue or Sack coat was worn for fatigue duty which was menial or manual labor in and around camp. Most sackcoat's were unlined but did have a large left breast pocket. The coat also features a roll collar and four medium brass buttons. The usual length for this coat was halfway between the hip and the knee. Even though this coat was issued for fatigue duty the average enlisted man would have worn this instead of his dress coat in the field. If one was to study photos from this period they would find that this was a very common practice.
The enlisted man's frockcoat was required for dress occasions for the Infantry, Heavy Artillery, and Ordnance Department. Probably the most famous of these unit's to wear this type of coat was the Iron Brigade. The coat is to reach between the half the distance between the hip and the knee. The trim on the collar and cuffs would of been red for Heavy Artillery and sky blue for Infantry. Just above the piping on the cuff you will notice a red stripe. This is a US Service stripe indicating five years of service. The fact that it is red with a sky blue background indicates "Service in War". The figure is also wearing the required leather belts to carry the cap box and cartridge box which is worn across his chest. On his head is a M-1858 Hardee Hat . According to US Army regulations this hat was for dress occasions. The typical enlisted men's hats also included a forage cap.