The Civil War resulted from multiple causes that interacted over decades. Use the framework SEEDS to organise them:
Slavery: The fundamental cause — the South's entire economy and social order depended on enslaved labour. As the North industrialised without slavery and its population grew faster, the South feared losing political power and with it the ability to protect slavery.
Economic Differences: By 1860, the North was an industrial economy of factories, free labour, and growing cities. The South was an agricultural economy based on slave-worked plantations. They had different interests in tariffs, infrastructure, and federal power — and increasingly different cultures.
Expansion Westward: Every new western territory forced the question: slave or free? The Missouri Compromise (1820), the Compromise of 1850, and the Kansas-Nebraska Act (1854) were all attempts to manage this — each one ultimately failed. "Bleeding Kansas" showed the issue could not be peacefully resolved.
Dred Scott Decision (1857): The Supreme Court ruled that enslaved people were not citizens and Congress had no power to ban slavery in territories. The North was outraged; abolitionists saw it as proof that slave power intended to spread slavery everywhere.
States' Rights: Southerners argued that states had the right to leave the Union — secession was constitutional. Northerners, led by Lincoln, denied this and were willing to fight to preserve the Union.
= Lincoln's Election, November 1860: When Lincoln won on a platform of restricting slavery's spread (with no southern electoral votes), the South saw secession as the only protection for their way of life. South Carolina left in December 1860; by February 1861 the Confederacy was formed.
This causation covers Why Did the Civil War Happen? The Causal Chain within The Making of America, 1789-1900 for GCSE History. Revise The Making of America, 1789-1900 in Component Group 4 — Period Studies for GCSE History with 14 exam-style questions and 18 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 7 of 16 in this topic. Use this causation to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for The Making of America, 1789-1900
Describe two features of the Louisiana Purchase of 1803.
Describe two features of the Indian Removal Act of 1830.
Quick recall flashcards
What was Manifest Destiny?
The belief, coined by journalist John O'Sullivan in 1845, that it was God's plan for the United States to expand across the entire North American continent. It provided moral justification for displacing Native peoples, annexing Texas, and fighting the Mexican-American War. Millions of Americans genuinely believed in it as a divine mission.
What was the Missouri Compromise of 1820?
An agreement to maintain the balance between slave and free states. Missouri entered as a slave state, Maine as a free state. A line at 36°30' N latitude was drawn — slavery permitted south of it, banned north of it. It preserved the Union for 30 years until the Kansas-Nebraska Act (1854) repealed it, leading to 'Bleeding Kansas' — a guerrilla war between pro-slavery and anti-slavery settlers.