Over the past decade or so, the move toward a more international perspective has been one of the most significant changes in the historiography of the American Civil War. In considering the response from nations around the world, especially the European powers intimately tied to the war raging in the United States, historians have recognized the importance of both Union and Confederate diplomacy abroad. This international approach— not without its critics— has worked to shift attention away from specific battles and military history in general.

I would highlight Don Doyle's The Cause of All Nations (2014) that recognizes how both Union and Confederate diplomats attempted to win of the support of European nations including the United Kingdom, France, Spain, and even the Papacy. Rather than focus on a single battle, Doyle argues that Lincoln's Emancipation Proclamation effectively ended any chance that the United Kingdom would openly support the Confederacy. As Doyle rightly notes, Confederate operatives in the UK had secured not only the production of naval vessels but also some inkling of hope that the UK would openly support the Confederacy against the Union. Though Confederates proposed a variety of reasons why the UK should support their cause, among the most powerful was the Confederate control of cotton. The UK had long relied on American cotton imports to create jobs for thousands of workers in their numerous mill cities. Though the American blockade was not a complete stranglehold on the South, cotton shipments had been disrupted and tensions grew in industrial centers. Many MPs believed the only way to ease tensions was to recognize the Confederate States of America and reopen direct trade. Any such recognition sentiment, however, was ended when Lincoln issued the Emancipation Proclamation on September 22, 1862. Although the the act did not effectively free any slaves— as the language specified that only slaves in rebellious states be freed— Doyle argues convincingly that Lincoln's proclamation effectively turned the American Civil War into a war about the future of slavery in the United States. This turning point then meant that nations like UK, which had outlawed slavery in 1833, could not openly support the Confederacy without being hypocritical to their own laws.

Doyle emphasizes that the American Civil War occurred in the wake of conservative measures across Europe to ensure that liberal revolutions, like those of 1848, would not occur again. During this time, monarchies once again regained the upper-hand in places like Spain and France, both of which sought to reinstitute their colonial control over the Americas while the United States was engulfed in their own war. In this monarchical atmosphere, the Confederate States of America, which relied on the oligarchical plantation system, seemed to have the ideological upper-hand. Rather than see the Emancipation Proclamation as the inevitable outcome of the American Civil War, recognizing the international context where liberal concepts like democracy and republicanism were on the ropes, highlights the dramatic importance of Lincoln's actions.

I would also emphasize, however, that Lincoln had been planning the Emancipation Proclamation for some time before its announcement. Only after the Battle of Antietam (September 17, 1862) did Lincoln feel the proclamation could be issued. If you'd like to place the emphasis on the battlefield, perhaps Antietam may have more significance than Gettysburg.

Sources: Don Doyle: The Cause of All Nations

Sven Beckert: Empire of Cotton

There are a few reasons Gettysburg is commonly seen as the turning point of the American Civil War. It took place almost exactly halfway through the war; it was the last general offensive Lee's army made onto U.S. soil during the war; the Confederates suffered serious casualties and lost the battle; Lee's army retreated on the same day Vicksburg fell; Lincoln gave a speech that became the most famous in American history.

However, these are all retrospective, and the actual experience of the war for people looking forward (as opposed to historians looking back) was much more doubtful. Edward Ayers made a great comment; if Gettysburg was as great a Union victory as is often trumpeted, it wouldn't have been the turning point of the war; it would been the end of the war. Not only did Lee successfully extricate his defeated army from its precarious position, with Union armies in front of him, behind him, and to his left, he also got months' worth of valuable supplies across the river, all drawn out of Union territory. The Union army had suffered serious casualties as well, which would drag down their combat effectiveness for the rest of the war. It would be ten months before the next general engagement with the Army of the Potomac, and in the interim, Lee would send two divisions and his best commander to the West, where they would be instrumental in winning the Army of Tennessee's only victory.

Yes, the Army of Northern Virginia was badly wounded at Gettysburg, but it did not die of those wounds. It fought the main Union army to a standstill for most of the rest of the war, and the Confederate peoples' faith in the army and its chief was unbroken. In the next campaign, it would inflict ten thousand casualties on the Union every week for six weeks, in a year where the presidential election was a referendum on the war.

While the spectacular stroke of luck in finding Special Order 191 during the Antietam Campaign has tantalized writers for over a century, Lee neither placed much faith in intervention by foreign powers, nor was the order as impactful on the campaign as often assumed. The order was found at Frederick, Maryland; the simple act of McClellan having marched there had already unraveled Lee's operational plan, before he acted on the discovery of S.O. 191.

Rather than foreign intervention, Lee's hopes rested on who he called 'the friends of peace' in the North; a significant segment of society in the U.S. came to oppose the war, for a variety of reasons. Some were outraged about the Lincoln administration's infringement of civil liberties; some opposed Emancipation as a fundamental blow against the Union itself; some believed that the war was actively undermining the possibility of reunion. Lee believed that, while most publicly stated that they wanted peace as the basis of reunion, this was mostly a red herring; once the fighting stopped at the war machine spun down, getting it started back up again would be a herculean task. Lincoln's faith in himself faltered, and even made his cabinet blindly sign a memorandum he revealed pledged them to continue the war even if the Republicans lost the election, as his opponent would have publicly committed himself to policies that would make victory impossible.

In this sense, the war is really only decided when the U.S. electorate decides to stick it out to the end with the election of 1864. Though the opposing nominee, George McClellan was a professed War Democrat, intent on fighting to the finish, the peace wing of the party wrote the platform at the Democratic national convention, declaring the war a failure and vaguely calling for a negotiated reunification -the Democratic press expressed the belief that electing a moderate would inspire the rise of a Southern peace party. Their nomination for Vice President, Pendleton, was viewed with suspicion as a 'peace-at-any-price' man. With the Democratic party divided, and with its presidential candidate refusing to engage with his campaign publicly or privately, Lincoln won the popular and electoral vote handily. True blue Unionists had always been the majority, and Lincoln had succeeded in convincing the people that emancipation was necessary to preserve the Union; it had been the institution that had divided the country in the first place, and soldiers worried that a peace that preserved slavery would risk another civil war down the line.

Feel free to hit me with any follow up questions!