Which soldiers in the civil war were union?

The soldiers of the Army of the United States were known as the 'Union' during the US Civil War. The soldiers of the opposing side, the Confederate States Army, were the rebels.
The soldiers of the Army of the United States were known as the 'Union' during the US Civil War. The soldiers of the opposing side, the Confederate States Army, were the rebels.

The soldiers of the Army of the United States were the 'Union' during the US Civil War. The soldiers of the opposing side, the Confederate States Army were the rebels.
The soldiers of the Army of the United States were the 'Union' during the US Civil War. The soldiers of the opposing side, the Confederate States Army were the rebels.