Which event demonstrated the misconception that the Civil War would be a short conflict with a swift resolution?

The Battle of Bull Run, fought on July 21, 1861, is often cited as the event that exemplified the widespread belief among both the Union and Confederate supporters that the Civil War would be a brief and decisive conflict. Prior to this battle, many people anticipated that it would take only a single engagement to resolve the issues between the North and South, allowing soldiers to return home soon after their enlistments.

The outcome of the Battle of Bull Run contradicted these expectations, as Confederate forces achieved a significant victory against the Union army. The unexpected intensity of the engagement and the subsequent realization of the war’s complexity and the determination of both sides shocked the public. This battle was a wake-up call that highlighted the grim reality of a prolonged conflict, which would extend over four years with immense loss of life and resources. The misjudgment about the war’s duration became a critical turning point in how both soldiers and civilians perceived the ongoing struggle.