The American Civil War happened between the years 1861 and 1865 in the United States after several slave states declared their secession from the south and form the Confederate States of America, known as "Confederation" or "South". The states that have not rebelled became known as "Union" or simply the "North". The war had its origin in the controversial issue of slavery.
In the presidential election of 1860, Republicans, led by Abraham Lincoln opposed the expansion of slavery in the territories under the jurisdiction of the United States. Lincoln won, but before his inauguration on March 4, 1861, seven slave states with economies based on the production of cotton formed the Confederacy. The then Democratic president, James Buchanan, and Republicans rejected the secession of the south. In his inaugural address, Lincoln stated that his administration would not start a civil war. Confederate forces took several federal forts in the territory claimed by the Confederacy. A peace conference in 1861 did not achieve any results, and both sides prepared for war. The Confederates assumed that European countries were so dependent on the cotton trade that would eventually intervene in the conflict, however, no country has intervened or acknowledged the existence of the new Confederate States of America.
Hostilities began on April 12, 1861, when Confederate forces took Fort Sumter, a strong key held by Union troops in South Carolina Lincoln urged each state to provide troops to retake the fort, and consequently four slave states joined the Confederacy, bringing the total to eleven members. The Union, however, soon controlled the border states and established a naval blockade that crippled the southern economy. In the summer of 1862, the Union destroyed the Confederate Navy and split the Confederacy in two from the Mississippi River. The Union used many human and material resources to attack the Confederacy in all directions. The Confederate army failed in its defense, leading to the surrender of his major general on April 9, 1865. All Confederate generals surrendered this summer.
The American Civil War was one of the first true industrial wars. Railroads, the telegraph, steamships, and mass-produced weapons were employed extensively. The mobilization of factories, mines, shipyards, banks, transport and food civilians foreshadowed World War. The conflict was the deadliest war in U.S. history.