Who fought in the the civil war?

The main participants in the Civil War were the United States of America and the Confederate States of America. The North employed many immigrants who were arriving primarily from Europe. Because of this, and because its population was greater to begin with, it could readily replace its losses. German, Irish, Italian, Hungarian immigrants were allowed to form their own units. The North also employed its Blacks to fight in segregated units. Blacks comprised 10% of the entire Union Army. Additionally, 13,000 Hispanics fought in the war under the confederacy and the others for the union. Approximately 3,600 Native Americans served in the Union Army during the war. Among the Cherokees one party went for the North and the other fought for the South.
The Union and confederacy.

In England, it was the Roundheads and the Cavaliers, in the most recent civil war.