What major conflict was fought between 1861 and 1865 in the United States?

The major conflict fought between 1861 and 1865 in the United States is indeed the American Civil War. This war was primarily centered around the issues of slavery and states' rights, and it pitted the Northern states (the Union) against the Southern states (the Confederacy).

The American Civil War arose following deep-rooted economic, social, and political differences between the North and South, particularly regarding the legality and morality of slavery. The election of Abraham Lincoln in 1860, who opposed the expansion of slavery into the territories, prompted a series of Southern states to secede from the Union, leading to the outbreak of hostilities in April 1861 at Fort Sumter in South Carolina.

The Civil War involved significant battles, such as those at Gettysburg and Antietam, and resulted in immense loss of life and destruction. It also set the stage for significant changes in American society, including the eventual abolition of slavery through the Thirteenth Amendment in 1865. Understanding this conflict is crucial for appreciating the social and political transformations that shaped the United States in the latter half of the 19th century.