who declared war to start the civil war
American Civil War The American Civil War was fought in the United States from 1861 to 1865. The result of a long-standing controversy over slavery, war broke out in April 1861, when Confederates attacked Fort Sumter in South Carolina, shortly after President Abraham Lincoln was inaugurated. The nationalists of the Union proclaimed loyalty to the U.S. Constitution. They faced secessionists of the Confederate States of America, who advocated for states' rights to expand slavery.
Origins of the American Civil War Historians debating the origins of the American Civil War focus on the reasons why seven Southern states declared their secession from the United States (the Union), why they united to form the Confederate States of America (simply known as the "Confederacy"), and why the North refused to let them go. While most historians agree that conflicts over slavery caused the war, they disagree sharply regarding which kinds of conflict—ideological, economic, political, or social—were most important.[1]