The two opposing forces during the American Civil War were the Union (the northern states) and the Confederacy (the southern states). The conflict arose primarily over issues such as slavery, states’ rights, and economic disagreements. The Union sought to preserve the nation and abolish slavery, while the Confederacy aimed to maintain their way of life. This war, fought from 1861 to 1865, resulted in significant loss of life and ultimately led to the end of slavery in the United States.