Final answer:
The inevitability of the Civil War can be attributed to escalating tensions between the North and South, especially over slavery, culminating with the election of Abraham Lincoln, the secession of Southern states, and the attack on Fort Sumter.
Step-by-step explanation:
John Green, a historian and author, might attribute the inevitability of the Civil War to a series of events and tensions that arose between the proslavery South and the antislavery North. Central to these tensions was the issue of whether the nation would be slave or free, with events such as the Kansas-Nebraska Act of 1854, which allowed for popular sovereignty on the issue of slavery and heightened regional tensions.
The election of Abraham Lincoln in 1860 was a significant watershed event, representing the culmination of the increasing tensions. Even before Lincoln took office, seven Deep South states seceded, forming the Confederate States of America, dedicated to maintaining racial slavery and White supremacy.
Efforts at compromise, such as the Crittenden proposal and the Corwin Amendment, failed, and with the Confederate attack on Fort Sumter, the Civil War began. While the Kansas-Nebraska Act and the economic, cultural, and philosophical differences between the North and South contributed to the coming of the war, it was the secession of the Southern states and the subsequent attack on Fort Sumter that turned those tensions into an inevitable conflict.