Army Structure

What Makes an Army?

Civil War battles are fought by armies made up of three branches: infantry, cavalry, and artillery. At the Battle of Kennesaw Mountain, General William T. Sherman's Union army had nearly 100,000 men. General Joseph E. Johnston had 65,000 in the Confederate Army. Today, American armies are designated by numbers. In the Civil War, armies were known by names. Union armies were usually named for major rivers. The Confederates named their armies for the states or regions in which they campaigned.

Armies are complicated organizations. To control such large numbers of men, armies are divided into levels of command. Starting from the bottom, when a man enlisted in the army, he joined a company of about 100 men, commanded by a captain and two lieutenants. Ten companies from a particular state were combined into a regiment commanded by a colonel. For example, a man might be a member of B Company of the 63rd Georgia Regiment.

 

Visual representation of an army structure.

 

Brigades, commanded by a brigadier general, were made up of five regiments. They averaged about 1,500-2,000 soldiers. Three or four brigades composed a division (6,000 to 8,000 soldiers) commanded by a major general. Southern units were known by the names of their Generals and were usually men from the same state. Numbers were used to designate the northern units.

A Corps (pronounced core) was composed of three or four divisions. It usually had artillery attached. A corps was commanded by a major general in the Union Army or a lieutenant general in the Confederate Army. As with the brigades and divisions, Confederate corps were named after their generals and Union corps were given numbers (usually Roman numerals).