Final answer:
Abraham Lincoln believed the Civil War would end slavery and ensure the Union's preservation, ultimately strengthening the federal government and ensuring the nation's unity.
Step-by-step explanation:
Abraham Lincoln believed that the Civil War would bring an end to slavery and preserve the Union. Initially focused on maintaining the Union, his perspectives evolved as the war continued, culminating in the issuance of the Emancipation Proclamation in 1863 and setting the stage for the eventual abolition of slavery. The ultimate effect of the Civil War, as Lincoln saw it, would not be the division of the country but rather its unification as a nation where slavery was no longer a divisive force.
Lincoln's famous quote, “A house divided against itself cannot stand,” exemplified his belief that the United States could not endure permanently half slave and half free. The Civil War decisively shifted power towards the federal government, contrasting with the pre-war balance of power and ensuring the permanence of the Union.