Title: American Civil War
Content: African Americans in the American Civil War ; German Americans in the American Civil War ; Irish Americans in the American Civil War ; Italian Americans in the American Civil War ; Native Americans in the American Civil War 
Title: American Civil War
Content:  The American Civil War (April 12, 1861 – May 9, 1865) (also known by other names) was a civil war in the United States fought between the Union (states that remained loyal to the federal union, or "the North") and the Confederacy (states that voted to secede, or "the South"). The central cause of the war was the status of slavery, especially the expansion of slavery into territories acquired as a result of the Louisiana Purchase and the Mexican–American War. On the eve of the civil war in 1860, four million of the 32 million Americans (~13%) were enslaved black 
Title: Native Americans in the United States
Content:   Native Americans served in both the Union and Confederate military during the American Civil War. At the outbreak of the war, for example, the minority party of the Cherokees gave its allegiance to the Confederacy, while originally the majority party went for the North. Native Americans fought knowing they might jeopardize their independence, unique cultures, and ancestral lands if they ended up on the losing side of the Civil War. 28,693 Native Americans served in the Union and Confederate armies during the Civil War, participating in battles such as Pea Ridge, Second Manassas, Antietam, Spotsylvania, Cold Harbor, and in Federal assaults on Petersburg. A few Native American tribes, such as the Creek and the Choctaw, were slaveholders and found a political and economic commonality with the Confederacy. The Choctaw owned over 2,000 slaves.
Title: Outline of the American Civil War
Content: Foreign enlistment in the American Civil War ; African Americans in the American Civil War ; German Americans in the Civil War ; Hispanics in the American Civil War ; Italian Americans in the Civil War ; Irish Americans in the American Civil War ; Native Americans in the American Civil War 
Title: Italian Americans in the Civil War
Content:  Italian Americans in the Civil War are the Italian people and people of Italian descent, living in the United States, who served and fought in the American Civil War mostly on the side of the Union. A contingent of soldiers from the former Kingdom of the Two Sicilies fought on the Confederate side, with most of these having been former prisoners of war who had fought against Giuseppe Garibaldi during his invasion of the Two Sicilies. Between 5,000 and 10,000 Italian Americans fought in the civil war.
Title: Late modern period
Content:   The American Civil War began when seven Southern slave states declared their secession from the U.S. and formed the Confederate States of America, the Confederacy (four more states joined the Confederacy later). Led by Jefferson Davis, they fought against the U.S. federal government (the Union) under President Abraham Lincoln, which was supported by all the free states and the five border slave states in the north. Northern leaders agreed that victory would require more than the end of fighting. Secession and Confederate nationalism had to be totally repudiated and all forms of slavery or quasi-slavery had to be eliminated. Lincoln proved effective in mobilizing support for the war goals, raising large armies and supplying them, avoiding foreign interference, and making the end of slavery a war 
Title: United States Army
Content:   The American Civil War was the costliest war for the U.S. in terms of casualties. After most slave states, located in the southern U.S., formed the Confederate States, the Confederate States Army, led by former U.S. Army officers, mobilized a large fraction of Southern white manpower. Forces of the United States (the "Union" or "the North") formed the Union Army, consisting of a small body of regular army units and a large body of volunteer units raised from every state, north and south, except South Carolina. For the first two years, Confederate forces did well in set battles but lost control of the border states. 
Title: Hispanics and Latinos in the American Civil War
Content:  fought for the Union during the American Civil War. It was also known as the "Federal Army", the "U.S. Army", the "Northern Army" and the "National Army". It consisted of the small United States Army (the regular army), augmented by massive numbers of units supplied by the Northern states, composed of volunteers as well as conscripts. The "New Mexico Volunteer Infantry", with 157 Hispanics officers, was the Union unit with the most officers of that ethnic background. Besides Colonel Miguel E. Pino and Lieutenant Colonel Jose Maria Valdez who belonged to the 2nd New Mexico Volunteer Infantry, the New Mexico Volunteer Infantry 
Title: Confederate States Army
Content:  Native Americans served in both the United States and Confederate military during the American Civil War. They fought knowing they might jeopardize their freedom, unique cultures, and ancestral lands if they ended up on the losing side of the Civil War. During the Civil War 28,693 Native Americans served in the U.S. and Confederate armies, participating in battles such as Pea Ridge, Second Manassas, Antietam, Spotsylvania, Cold Harbor, and in Federal assaults on Petersburg. Many Native American tribes, such as the Creek, the Cherokee, and the Choctaw, were slaveholders themselves, and thus, found a political and economic commonality with the Confederacy. At the beginning 
Title: Military history of African Americans in the American Civil War
Content:  A large contingent of African Americans served in the American Civil War. The 186,097 Black men who joined the Union Army included 7,122 officers and 178,975 enlisted soldiers. Approximately 20,000 black sailors served in the Union Navy and formed a large percentage of many ships' crews. Later in the War, many regiments were recruited and organized as the United States Colored Troops, which reinforced the Northern side substantially in the last two years. Both Northern Free Negro and Southern runaway slaves joined the fight. Throughout the course of the war, black soldiers served in forty major battles and hundreds of more minor skirmishes; sixteen African Americans received the Medal 

Question: who took part in the american civil war?
Answer: nationalists of the Union.