The first large battle of the war, at Bull Run, Virginia (also known as First Manassas) near Washington, stripped away any illusions that victory would be quick or easy. It also established a pattern, at least in the Eastern United States, of bloody Southern victories that never translated into a decisive military advantage for the Confederacy.
In contrast to its military failures in the East, the Union was able to secure battlefield victories in the West and slow strategic success at sea. Most of the Navy, at the war's beginning, was in Union hands, but it was scattered and weak. Secretary of the Navy Gideon Welles took prompt measures to strengthen it. Lincoln then proclaimed a blockade of the Southern coasts. Although the effect of the blockade was negligible at first, by 1863 it almost completely prevented shipments of cotton to Europe and blocked the importation of sorely needed munitions, clothing, and medical supplies to the South.
