Final answer:
The Kansas-Nebraska Act is noted by historian James McPherson to be a major event pushing the nation toward the Civil War due to its allowance of popular sovereignty in new territories, exacerbating regional tensions. The Civil War's inevitability is debated, with factors such as political compromises and differing economic developments being potential avenues to avoid the conflict. It had a lasting impact on political dominance by the federal government, economic shifts in both North and South, and significant social changes, including emancipation.
Step-by-step explanation:
Historian James McPherson points to the Kansas-Nebraska Act as a crucial precipitating factor leading up to the American Civil War. The act involved the application of 'popular sovereignty' to the territories, essentially allowing them to decide whether they would be slave-holding or free. This created a rush to populate the territories with pro-slavery or anti-slavery settlers and resulted in violent confrontations known as 'Bleeding Kansas'. It's arguable that this act significantly escalated the regional tensions that existed over slavery, serving as a stepping stone to the eventual conflict that erupted into Civil War.
Whether the Civil War was avoidable is a matter of historical debate. The war was not just about slavery but also about various political, economic, and social tensions. Some argue that the conflict became inevitable when the fundamental disagreements between North and South became irreconcilable, which could have been before or because of the Kansas-Nebraska Act. What might have prevented war is extensive, but potential solutions could include better political compromises, less aggressive policies on the expansion of slavery, or different economic developments in the South.
The impact of the Civil War on American life was profound. Politically, it led to the supremacy of federal government power over the states. Economically, the destruction of the Southern plantation economy and the consolidation of the Northern industrial economy were pivotal. Socially, the war saw significant shifts involving draft riots, divisions between rich and poor, and the pivotal emancipation of enslaved people.