Building an Army (Civil War)

To the non-military buff, the organization and terminology used for Civil War armies can be very confusing. The Union and the Confederate Armies had different names depending upon their location. But despite the many names both of the armies were organized in a similar fashion including a structure of corps, divisions, and brigades. But what were these different organizations and how did they all fit in to one huge force?

Fort Sumter National Monument
Organization Affiliation
National Park Service
Lesson Plan Subjects