The correct answers are B, C and D.
-Many Southerners believed that states had the power to choose which federal laws to follow.
As a result, among other things, of a historical controversy over slavery and against attempts by the federal government to take powers that did not correspond to it in a constitutional manner, the war broke out in April 1861, when the forces of the Confederate States of America attacked Fort Sumter in South Carolina, shortly after President Abraham Lincoln took office. The nationalists of the Union proclaimed loyalty to the Constitution of the United States. They clashed with secessionists from the Confederate States, who defended the rights of states to expand slavery.
-People on both sides knew the war would be long and bloody, but supported it anyway.
The Union and the Confederation quickly raised voluntary and conscript armies that fought mainly in the South for four years.
-Lincoln gave the war a new goal, ending slavery, with the Emancipation Proclamation.
The Emancipation Proclamation expanded the objectives of the Civil War. While slavery had been a major problem that led to war, Lincoln's only mission at the beginning of the war was to maintain the Union. The Proclamation made slaves an explicit objective of the Union's war effort.
