Although the Civil War was by nature a domestic affair, foreign policy played an important role in the progress of the conflict. In the spring of 1861, Secretary of State Seward had suggested that disunion could be avoided entirely if the United States chose to engage itself in a European war. Although perhaps correct in its reasoning, Seward's proposal was of dubious merit, and was never seriously considered by Lincoln.
By the summer of 1861, Britain and France had pledged their neutrality in the conflict. Such a pledge was a weak endorsement of the Union at best. While Queen Victoria of England and Emperor Napoleon III of France recognized the southern states as belligerents, this did not prevent the Confederacy from attempting to court the European powers for aid and potential alliances. By the Confederate logic, an old-world monarchy would be pleased to see the emerging system of democracy undermined. Further, an aristocracy tends to sympathize with an aristocracy. Additionally, the European nations were dependent on the southern states for their cotton supply.
In November, near disaster visited the Union with the uproar of the Trent Affair. As per Scott's Anaconda Plan, a Union captain seized two Confederate representatives aboard a British mail steamer and had them imprisoned in Boston. This act of aggression was met with considerable outrage overseas, and Britain found itself provoked to point of declaring war. After 11,000 British troops were sent to Canada, Lincoln finally decided to free the Confederates in order to avoid an international fiasco.
Nevertheless, many northerners continued to agitate for war with Britain, preserving fresh memories of the War of 1812, when control of the seas in the Western hemisphere had also been a point of conflict. In fact, British industry would continue to supply the Confederacy with what amounted to war ships until an act of the British parliament prevented further sale in September of 1863. While this was a sweeping extension of parliamentary power over the British economy, it was justified as a necessary action under the very real threat of war from the Union.
Although the British government sought to disassociate itself from the Confederacy after the Trent Affair, certain members of parliament continued to keep a watchful eye on the progress of the Civil War. William E. Gladstone, who would eventually accede to the prime ministership, gave a speech in the autumn of 1862 in which he dared to "anticipate with certainty the success of the Southern States so far as regards their separation from the north." While this was something of a radical opinion in Britain, the bald fact that a credible politician could maintain that opinion was made possible by a string of Union mistakes and Southern successes in the field.
After the disaster at First Manassas, Lincoln replaced McDowell with the upstart McClellan, who took command of the eastern theater on the strength of his successes in Western Virginia. But after further defeats in Virginia at Wilson's Creek and Ball's Bluff during the month of October, McClellan decided to regroup with his Union forces for the duration of the winter. The Anaconda Plan would suffice as McClellan prepared for his Peninsular Campaign against Richmond in the spring.
Recognizing McClellan's increasingly central role in the Union's fortunes, Lincoln chose him to take command as overall General of the Union forces after the aging Scott resigned in November. With this encouragement, and well rested from months of planning, McClellan launched his amphibious assault of Richmond in March of 1862. At sea, the Confederate ironclad warship Virginia wreaked havoc with the Union navy, sinking two wooden ships before an inconclusive clash with the Union ironclad Monitor. Ultimately, by sheer virtue of numbers, Union forces were able to push south down the Potomac River and through the Chesapeake Bay, landing at Fort Monroe and preparing to push inland.
The long winter had enabled the Confederates to dig in and fortify their position around Richmond, and although the Union forces enjoyed an early victory at Yorktown in early May, their progress was slow. After three weeks of gradual advancement, they came within striking distance of Richmond. The Confederate capital prepared for evacuation. Poised to topple the enemy, McClellan's aims were undermined when he received fewer men from Lincoln than anticipated. In the ensuing week of fighting known today as the Seven Days' Battles, forces under Confederate Generals Jackson and Lee dominated the Shenandoah Valley, leaving McClellan no choice but to retreat from Richmond on July 1. Between the Confederacy and the Union, a combined 35,000 casualties (those numbered dead or wounded) were left behind.
After McClellan's aborted Peninsular Campaign, it quickly became clear that the war would be no short affair. Mere days after the Union defeat in the Seven Days' Battles, Lincoln called for the enlistment of 300,000 three-year commitments. But with this appeal for reinforcements left unheeded, Lincoln was subsequently forced to revise his request, lowering the term of service from three years to nine months.
Fortunately for Union morale, their forces fared markedly better in western theaters. A Confederate invasion of New Mexico was quickly turned back in the spring of 1862. In late April, David Farragut led the seizure of the key port of New Orleans. Meanwhile, General U.S. Grant led a push south along the western front, moving from Ohio to Alabama in a few short weeks. Although progress was steady, losses were heavy. The most intense fighting occurred in Tennessee, where Grant succeeded in reclaiming several important forts, and moved on to capture Nashville in late February.
As Grant pushed on toward Memphis at the beginning of April, his armies were caught by surprise at the Battle of Shiloh, one of the bloodiest of the civil war. After three days of intermittent warfare, 20,000 casualties were left behind. Although the Union had initially been caught unawares, reinforcements had bolstered their cause, and by midsummer the entire state of Tennessee had fallen under Union control, with Andrew Johnson acting as military governor.
Once again, Lincoln looked to one of his successful generals in the West to assume command of his overall campaign. This time the chosen man was Henry Halleck, who took command of the Union forces ten days after the Seven Days' debacle. Despite McClellan's failure in the Peninsular Campaign, Lincoln retained him as commander of the eastern campaign, and the Union forces regrouped to make yet another assault on Richmond.
Even in the face of manpower shortages, the Union began to advance on Richmond again in July. Before long, McClellan realized the disadvantages of his position and began to withdraw, but General John Pope continued to press forward. In late August, Pope was routed by Confederate forces under the command of Stonewall Jackson at Second Manassas (also known as Bull Run). The Union alone lost 15,000 men in the slaughter, and they duly retreated from Virginia to mobilize once more in Washington.
Encouraged by this string of military successes, Lee decided to go on the offensive in hopes of capitalizing on Union indecision. He led Confederate forces across the Union line into Maryland during the first week of September, throwing Washington into a flurry under the threat of possible attack. In the process of this bold shift in strategy, Lee lost 30,000 troops, not to death or disease but to defection. These conscientious objectors explained that they had enlisted to protect the Confederacy, not to invade the Union.
Even in spite of this blow to Confederate solidarity, Lee knew he would be able to pose a serious threat to Union security. His strategy was not to conquer the Union, but rather to damage its overwhelming military capacity. In mind of this goal, he made for Harrisburg, in an attempt to disable the railroad hub there. After Jackson's successful tactical victory at Harpers Ferry, Virginia, Lee and Jackson met at Sharpsburg, Maryland on September 16, poised to move on to Pennsylvania.
But the next day, McClellan confronted the Confederate advance at the Battle of Antietam. After what amounted to a virtual deadlock, McClellan was able to turn back the combined rebel forces. In a single morning and afternoon of fighting, 20,000 men were killed. It was the bloodiest day of the war. Nevertheless, Lee boldly held his line, waiting for another Union attack. Paralyzed by his heavy losses, McClellan failed to pursue further, and Lee retreated south across Potomac, his first offensive against the Union forces a failure.
By this point, the war was over a year old. Each side had launched a series of offensives, and by and large these offensives had been fruitless. Lee, for one, recognized that the powerful Union would eventually outlast the failing Confederate arsenal in a drawn-out war. Thus, after his retreat from Antietam, Lee recommended to President Davis that a peace settlement be negotiated recognizing Confederate independence. But with no such settlement forthcoming, the Union began to revise its strategy, shifting into a mode of total war that would at once have devastating consequences and glorious results.