had significant diplomatic consequences. Confederate agents abroad were generally received more coolly, if at all, after news of the city's capture reached London and Paris. Union victory at Battle of Antietam (September 1862) The Battle of Antietam, fought September 17, 1862, was the bloodiest single day of conflict in American military history. But it also had two strategic consequences. Although considered a tactical draw between the Army of the Potomac and the much smaller Army of Northern Virginia, it marked the end of Robert E. Lee's invasion of the North. One of his goals was to entice the slave-holding state of Maryland to join the Confederacy, or at least recruit soldiers there. He failed in that objective; he also failed in marshaling Northern fears and opinions to pressure a settlement to the war. But more strategically, George B. McClellan's victory was just convincing enough that President Lincoln used it as justification for announcing his Emancipation Proclamation. He had been counseled by his cabinet to keep this action confidential until a Union battlefield victory could be announced, lest it appear to be an act of desperation. Along with its immense effect on American history and race relations, the Emancipation Proclamation effectively prevented the British Empire from recognizing the Confederacy as a legitimate government. The British public had strong anti-slavery beliefs and would not have tolerated joining the pro-slavery side of a fight where slavery was now a prominent issue. This greatly diminished the Confederacy's hopes of surviving a lengthy war against the North's suffocating naval blockade. Support from France was still a possibility, but it never came to pass. Antietam and two other coincident failed actions—Braxton Bragg's invasion of Kentucky (sometimes called the "high-water mark of the Confederacy in the Western Theater") and Earl Van Dorn's advance against Corinth, Mississippi—represented the Confederacy's only attempts at coordinated strategic offensives in multiple theaters of war. Stonewall Jackson's death (May 1863) After winning the Battle of Chancellorsville, the Army of Northern Virginia lost Lt. Gen. Stonewall Jackson to pneumonia following a friendly fire accident. His death was a blow to the morale of the Confederate army, as he was one of its most popular and successful commanders. Two months later, Robert E. Lee had no general with Jackson's audacity available at the Battle of Gettysburg. Many historians argue that Jackson might have succeeded in seizing key battlefield positions (such as Culp's Hill and Cemetery