Final Answer:
The events that pushed the United States toward a military confrontation were primarily instigated by the Confederate States, as they initiated the Civil War. The main cause was rooted in the Southern states' desire to preserve the institution of slavery and protect their economic and social structure, which they perceived as threatened by the growing anti-slavery sentiment in the Northern states.
Step-by-step explanation:
The responsibility for pushing events toward a military confrontation in American history lies predominantly with the Confederate States. The key factor leading to the Civil War was the fundamental disagreement over the issue of slavery. The Southern states, heavily reliant on slave labor for their agrarian economy, were concerned about the potential abolition of slavery and the impact it might have on their way of life.
As tensions escalated, several events, such as the Missouri Compromise, the Compromise of 1850, and the Kansas-Nebraska Act, failed to provide lasting resolutions to the slavery issue. The election of Abraham Lincoln as president in 1860, representing the anti-slavery Republican Party, further intensified Southern fears of federal interference with their institutions.
The secession of Southern states and the formation of the Confederate States of America marked a decisive move toward military confrontation. The Confederate attack on Fort Sumter in April 1861 triggered the start of the Civil War. In essence, the Southern states, driven by the desire to maintain their economic and social structure based on slavery, played a significant role in pushing the nation toward the military conflict that became the American Civil War.