Answer:
Slavery and states' rights
Economic differences between the North and South
Political differences and the election of Abraham Lincoln
Step-by-step explanation:
I believe the most significant reason the Union and Confederacy went to war was slavery and states' rights. The issue of slavery was deeply intertwined with states' rights, as Southern states argued that they had the right to maintain slavery within their borders and that the federal government had no authority to interfere with this institution. The election of Abraham Lincoln, who was opposed to the expansion of slavery, further exacerbated tensions between the North and South and ultimately led to the outbreak of war. The economic and political differences between the two sides also played a role, but the issue of slavery was the main cause of the conflict.