The Order of Battle of the United States Army World War II European Theater of Operations is an incredible resource for understanding how the various units in the Normandy Campaign were organized and how they interacted. Knowing this information will help you know where the unit you chose fits in the larger picture of the operation.
It is organized by Division and provides information about:
Occasionally the link above does not work and a digitized version of the Order of Battle of the United States Army World War II European Theater of Operations -- From the U.S. Army Center of Military History is available from the US Archives. Use the table of contents to find the division you are looking for.
For example, if the unit you chose is part of the 70th Infantry Division, the entry would look like this:
**Click on each photo to enlarge it**
This is the Order of Battle as provided by the Rowan Reader.
