The American Civil War (1861-1865) was a pivotal conflict in the nation's history, pitting the Union (the Northern states) against the Confederacy (the Southern states) in a struggle that would ultimately determine the fate of slavery, states' rights, and the unity of the country. The war was sparked by the secession of 11 Southern states from the Union, which were determined to preserve and expand the institution of slavery. The Union, led by President Abraham Lincoln, saw secession as a threat to the Constitution and the unity of the country, and responded with military force to preserve the Union and end the institution of slavery.
The war was fought on multiple fronts, with battles taking place in the Eastern and Western theaters, and resulted in the deaths of an estimated 620,000 to 750,000 soldiers and civilians. The Confederacy was ultimately defeated, and the war led to the abolition of slavery and a more centralized federal government. The American Civil War was a defining moment in American history, shaping the country's politics, society, and culture for generations to come.
*Image courtesy of the Library of Congress, The West Point Atlas of American Wars