The American Civil War (12 April 1861 – 26 May 1865) was fought in the United States between the Union (“the North”) and the Confederacy (“the South”), which was formed in 1861 by states that had seceded from the Union.

      The Civil War started because of uncompromising differences between the free and slave states over the power of the national government to prohibit slavery in the territories that had not yet become states. When Abraham Lincoln won election in 1860 as the first Republican president on a platform pledging to keep slavery out of the territories, seven slave states in the deep South seceded and formed a new nation, the Confederate States of America. The incoming Lincoln administration and most of the Northern people refused to recognize the legitimacy of secession. They feared that it would discredit democracy and create a fatal precedent that would eventually fragment the no-longer United States into several small, squabbling countries.

      The event that triggered war came at Fort Sumter in Charleston Bay on 12 April 1861. Claiming this United States fort as their own, the Confederate army on that day opened fire on the federal garrison and forced it to lower the American flag in surrender. Lincoln called out the militia to suppress this “insurrection.” Four more slave states seceded and joined the Confederacy. By the end of 1861 nearly a million armed men confronted each other along a line stretching 1200 miles from Virginia to Missouri.

      By the spring of 1865 all the principal Confederate armies surrendered, and when Union cavalry captured the fleeing Confederate President Jefferson Davis in Georgia on 10 May 1865, resistance collapsed, and the war ended. The long, painful process of rebuilding a united nation free of slavery began.

Sources: American Battlefield Trust and Wikipedia (24 August 2025)