The two sides of the American Civil War were the United States of America and the Confedreate States of America. The US was commonly referred to as the Union, while the CSA was referred to as the Confederates or the Rebels.
The northern forces were the United States Army. The southern forces were the Confederate States Army. The Confederate government planned to create a regular army, just like the US. The Confederate president was a graduate of the US Military Academy at West Point. Ninety-nine out of one hundred Confederate soldiers were "volunteers" instead of "regular" troops. The Confederacy formed a handful of "regular" regiments and commissioned a small number of regular officers. The vast bulk of Confederate officers actually held commissions in the "P. A. C. S.", the Provisional Army, Confederate States. Similarly, the northern army had only 16,000 men before the war, and many of these went south. Most northern soldiers were in non-regular, "volunteer" units and their officers held commissions as "U. S. V.", "United States Volunteers". Regular officers still held their commissions at their regular rank, but most served at a much higher "volunteer" rank. Once the war was over, they had to revert to their regular rank.
The two main field armies of the southern forces were in Virginia and Tennessee. The Virginia force was called the Army of the Potomac originally, but when Robert E. Lee assumed command of it in June 1862 he changed the name to the Army of Northern Virginia, because it was in the Department of Northern Virginia. The Confederacy had its entire territory divided into "departments". The commander of each department commanded all troops in the department, which would often be collectively called the army of that department. The other main Rebel army was the Army of Tennessee. The Confederates named their armies after a geographic area, while the Yankees named theirs after rivers.
The most famous northern army was the Army of the Potomac - not to be confused with the Confederate army with the identical name, mentioned above. The Union Army of the Potomac fought the old southern Army of the Potomac, which had changed its name to the Army of Northern Virginia. Similarly, the main opponent of the Confederate Army of Tennessee was the Union Army of the Tennessee, named after the River. Assisting against this Confederate force were the Union Army of the Ohio and the Army of the Cumberland. In the east there was also an Army of the James.
The Union army under US Grant was meant to take care of Robert E. Lee and the Army of Northern Virginia. It eventually succeeded - after the terrible Siege of Petersburg, which was simply a slugging match, with Grant knowing that the Confederates could not replace their losses. The surrender came when Lee's lines were so stretched that they couldn't hold.
The other Union army under Sherman was meant to destroy the Army of Tennessee under Joe Johnston (replaced by John Hood). It did not succeed in doing this. But Sherman had worked out his new strategy of attacking the infrastructure that supported the Confederate armies - devastating the rich farmland of Georgia and South Carolina. There were not enough enemy troops to stop him, although the talented Joe Johnston had been brought back to command what few Confederate units remained in that area. They surrendered about two weeks after Lee.
The very last major engagement of Union and Confederate forces was the Battle of Palmito Ranch on May 12-13, 1865 between armies under the command of Union General Lew Wallace, and Confederate General John G. Walker, though neither general participated in the battle, and ended with a force of 300 Confederates defeating over 1700 Federals. Some historians, as well as, the Official Record of the Civil War consider this battle to be a post-war engagement, and the Battle of Columbus to be the true last battle. It is worth mentioning that the official record of any war is written by the winner of said war, in this case the Union, and has been suggested that Union officials refused to recognize a Confederate victory as the final battle, particularly when 1700 - 1900 Union troops were defeated by 300 - 400 Confederates.
The last official battle of the Civil War was the Battle of Columbus on the Georgia/Alabama border on April 16, 1865, 2 days after Lincoln was killed, between Union General James H. Wilson, and Confederate General Howell Cobb and ended in a Union victory.
On a side note: In the Battle of Columbus a Confederate soldier named John Pemberton was injured by the slash of a sabre, and it was this injury that led him to become a pharmacist after the war preoccupied with creating formulas for pain killers and ultimately leading to the invention of Coca-Cola.
Also of note: Lew Wallace from Palmito Ranch, later gained notoriety as the Governor of New Mexico that offered a full pardon to Billy the Kid, but later reneged because of political pressure, and became somewhat famous as author of what was considered "the most influential Christian book of the nineteenth century" Ben-Hur: A Tale of the Christ.
"Republicans" and the "Free Staters".
The two sides of the Irish Civil War were the "Republicans" and the "Free Staters".
The civil war was the North and south or the Union and Confederates
The Central Powers and the Allies.
There are a great many names for the American Civil War depending on where you're from. I'll list a few of them. The War Between the States (officially adopted name) The War of Northern Agression The War of Southern Succession The Late Unpleasantness (used after the end of the Civil War) There are a great many others! I recommend studying this time period to get a greater feel for the opinions on both sides, and some of the names they came up with in both the North and the South.
The two sides were referred to as the Red Army (Bolsheviks and their revolutionary supporters) and the White Army ( nonrevolutionaries who either wanted the Tsar restored to the throne or depose Lenin and the Bolsheviks. In addition to the Reds and Whites there were the Greens, who were anarchists.
The two sides of the Irish Civil War were the "Republicans" and the "Free Staters".
Assuming that you mean the Civil War that took place in the United States - two alternate names are The War Between the States, and the The War of Northern Agression.
Union and confederate
the two sides during the US civil war were the union (North) and the confederacy (south)
Both sides in the Civil War were Americans. By definition a civil war occurs when two factions within a country go to war.
The civil war was the North and south or the Union and Confederates
ANSWER The American Civil War
rebs and yanks
There was the North (Union) and the South (Confederacy).
parliament and royalists
I think you are going for the idea of civil war.
The Royalists(Cavaliers) and the Parliment(roundheads). Oliver Cromwell was the leader of the Roundheads and Charles 1st was leader of the Cavaliers.