Editing Casus belli (section)

=== American Civil War ===
{{Further|Origins of the American Civil War|Battle of Fort Sumter#Decisions for war}}
While long-term conflict between the [[Northern United States|Northern]] and [[Southern United States|Southern States]] (mainly due to moral questions caused by [[Slavery in the United States|slavery]], as well as socio-economic disparities) was the cause of the [[American Civil War]], the [[Confederate States of America|Confederate]] [[Battle of Fort Sumter|attack on Fort Sumter]] (April 12–14, 1861) served as ''casus belli'' for the [[Union (American Civil War)|Union]].<ref name="Watson"/> Historian [[David Herbert Donald]] (1996) concluded that President [[Abraham Lincoln]]'s "repeated efforts to avoid collision in the months between inauguration and the firing on Ft. Sumter showed he adhered to his vow not to be the first to shed fraternal blood. But he also vowed not to surrender the forts. The only resolution of these contradictory positions was for the confederates to fire the first shot; they did just that."{{sfn|Donald|1996|p=293}} Confederate veteran [[William Watson (sergeant)|William Watson]] opined in 1887 that up until that point, U.S. Secretary of State [[William H. Seward]] had not been able to find 'a just cause to declare war against the seceded States', but Sumter gave him 'the ''casus belli'' he had sought'.<ref name="Watson"/> Watson lamented how [[Jefferson Davis]] and other Confederate leaders were 'vainglorious[ly]' celebrating the victory at Sumter, while forgetting that making the first move had given the Confederacy the immediate internationally negative reputation of being the aggressor, and had granted Seward 'the undivided sympathy of the North'.<ref name="Watson">{{cite book |last=Watson |first=William |title=Life in the Confederate Army: Being the Observations and Experiences of an Alien in the South During the American Civil War|url=https://books.google.com/books?id=VJpBAAAAYAAJ&pg=PA113 |access-date=August 5, 2014 |year=1887 |publisher=Chapman & Hall |location=United States |page=113|isbn=9780722282977 }}</ref>