Everything you need to master Unit 7 — World War I, the interwar period, the Great Depression, the rise of fascism, World War II, the Holocaust, and how 20th-century conflict reshaped the world order.
8–10% of the AP exam
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Unit 7 covers the era of global conflict from 1900 to the present — the two World Wars that reshaped the international order, the Great Depression that destabilized democracies, the rise of fascism in Italy and Germany, the horrors of genocide (Armenia, the Holocaust, Cambodia, Rwanda), and the dawn of the nuclear age.
The College Board wants you to understand how European maritime exploration connected the Americas to Afro-Eurasia for the first time, the Columbian Exchange that transformed biology and demography, the rise of the Atlantic slave trade as the economic engine of New World plantations, and how mercantilist policies and joint-stock companies built the first global economy.
Unit 7 makes up roughly 8–10% of the AP World History exam, but its consequences continue to shape the modern world — from the United Nations to the nuclear arms race to today's human rights frameworks.
Key terms preview
A taste of what you'll find in The Essentials and Flashcards.
Total War
War requiring complete mobilization of military, industry, and civilians; defined both World Wars and erased the line between soldiers and civilians.
Treaty of Versailles
1919 peace treaty ending WWI; punitive terms toward Germany helped fuel the rise of fascism and WWII.
Fascism
Authoritarian ultranationalist ideology that rose in Italy (Mussolini) and Germany (Hitler) amid economic crisis.
Holocaust
Nazi Germany's systematic genocide of six million Jews and millions of others (1941–45).
Great Depression
Global economic collapse starting in 1929 that destabilized democracies and helped fascists rise to power.
Atomic Bomb
Nuclear weapons used by the US against Hiroshima and Nagasaki (Aug 1945); ended WWII and inaugurated the nuclear age.
1. WWI was caused by nationalism, militarism, imperialism, and alliance systems
Franz Ferdinand's assassination was a trigger, not the cause. The underlying conditions — MAIN: Militarism, Alliances, Imperialism, Nationalism — turned a regional crisis into a global war.
2. The Treaty of Versailles planted the seeds of WWII
Punitive reparations, war guilt clauses, and territorial losses imposed on Germany created the economic devastation and national humiliation that Hitler later exploited.
3. WWII was the deadliest conflict in human history — and reshaped the world order
An estimated 70–85 million people died. The war ended European dominance, made the US and USSR superpowers, created the UN, and ushered in the nuclear age.
4. Genocide became a defining horror of the 20th century
The Armenian Genocide, the Holocaust, and later atrocities in Cambodia, Rwanda, and Bosnia share common features: dehumanizing propaganda, state power, and international failure to intervene.