This is an example of a regulation size first lieutenant's shoulder strap as worn by Union Army staff officers with that particular rank during the Civil War. This particular strap has one-quarter inch borders made of alternating groups of bright and dead bullion. The gold first lieutenant's bars do not meet the border and are slightly curved around the edges of the bars. This latter feature is rather uncommon among period straps that are originals. Staff officer shoulder straps can be found in all the various ranks, but the two most common ranks to be encountered as artifacts are those of major and first lieutenant, the ranks held by the regimental surgeon and assistant surgeon as well as other categories of staff officers. The next most common is that of captain, the rank held by many of the commissary officers. Staff straps of other ranks are less common, but do exist.
There were a number of categories of staff officers during the Civil War. Certain staff officer's were members of individual regiments. These were mustered with the staff and field officers and not assigned to individual companies. They included the regimental surgeon (a major) and assistant surgeon, adjutant and quartermaster (the last three all lieutenants). In addition to these officers there were staff officers assigned the the staffs of larger units, such as brigades, divisions, army corps and armies. Finally, there were a number of officers directly assigned to the staff departments of the army, such as the Ordnance Department or the Corps of Engineers. All of these officers wore the uniform of a staff officer as opposed to the uniform of regimental officers assigned to the combat arms of artillery, infantry, and cavalry. Certain officers were directly commissioned as staff officers and others were originally commissioned in combat branches and detailed to serve as staff officers on a temporary or permanent basis.