The Union defeat at Bull Run ended Northern
complacency about a quick victory. George McClellan and other early Union
generals proved unable to defeat the tactically brilliant Confederate armies
under Lee. The Union naval blockade put a slow but devastating economic noose
around the South.
The political and diplomatic dimensions of the
war quickly became critical. In order to retain the border states, Lincoln
first de-emphasized any intention to destroy slavery. But the Battle of Antietam
in 1862 enabled Lincoln to prevent foreign intervention and turn the struggle
into a war against slavery. Blacks and abolitionists joined enthusiastically
in a war for emancipation, but white resentment in part of the North created
political problems for Lincoln.
The Union victories at Vicksburg in the West
and Gettysburg in the East finally turned the military tide against the South.
Southern resistance remained strong, but the Union victories at Atlanta and
Mobile assured Lincolns success in the election of 1864 and ended the
last Confederate hopes. The war ended the issues of disunion and slavery,
but at a tremendous cost to both North and South.