READ CAREFULLY THE ASSIGNMENT INSTRUCTIONS GIVEN TO YOU BY YOUR SECTION INSTRUCTOR. Direct questions about the assignment instructions to your section instructor.
Basic assignment materials:
Your assignment instructions may refer you to Ballard's Battle of Antietam: Staff Ride Guide as the main secondary source you should consult to get an overview of the course of the Battle of Antietam. But what is a staff ride? The resource below may help you learn more about Ballard's work and what it is. It is not necessary to consult this, and you can simply start with Ballard, but it may help some to understand how and why the U.S. Army uses staff rides in professional military education.
Make certain that you know the subordinate units of your brigade (that is, which regiments were assigned to it and together composed that brigade).
Make certain that you know which units were near or adjacent to your brigade at various points of time in the action.
To gain knowledge of these matters, consult an Order of Battle of the Union and Confederate forces at Antietam.
Q. What is an Order of Battle?
A. An Order of Battle is a document that explains the organization and composition of a military force at some period of time, whether a specific point in time or over some longer period. The term originates from eras (such as the early modern period) when commanders documented the actual arrangement on the field of particular units in a battle line. “Order of Battle” for military historians, however, has come to mean any document (whether in the form of formatted text, a chart, table, etc.) that makes clear the hierarchical command relationships and organizational structure of a military force. It is usually used to make clear the composition of larger forces, whether the entire military force of one nation or coalition a part thereof, such a a field army, etc.
Order of Battle
The armies that fought at Antietam were quite large, and having at hand a full order of battle of the both the Union and Confederate sides will likely be of great help. At the very minimum, know which regiments composed your brigade, and know the division of which your brigade was part. When you start examining the OR, you may wish to look for reports, correspondence, other documents, etc. not just from your brigade but from each of its component regiments, etc. You may also use the Order of Battle for Antietam in concert with various maps to increase your understanding of which opposing units your brigade faced and which nearby friendly units’ actions might have affected your unit.
Understanding the Order of Battle. Note that during the American Civil War, unlike later periods, Brigades and Divisions were not permanent organizations with a numerical designation but rather designated by the name of their commander. Regiments, however, did have a consistent designation. That designation consisted of (usually) a number, name of a state, and the arm of service, e.g. 15th New York Infantry. This applies to state volunteer units which composed the majority of the Union Army. It may be helpful for you to know the names of commanders of individual regiments; some Civil War orders of battle list these and some do not. Also note that if a commander was killed or wounded in action and someone else took over command of his unit, some orders of battle will list this as well.
A basic order of battle for Antietam is found in pp. 54-74 of Ballard, Battle of Antietam (CMH Staff Ride Guide)
Consult the maps in Ballard and the maps referred to in your assignment instructions
How Do I?