Advances in Technology and Exchange after 1900
New communication technologies, transportation systems, energy sources, agricultural innovations, and medical breakthroughs reduced geographic distance and transformed human populations after 1900.
AP World Unit 9 Review: 1900 to Today
- 8–10% of AP multiple choice
- 9 topics
- AP exam review verified for 2027
Globalization after 1900 was driven by new technologies in communication, transportation, and energy; free-market economic policies; and international institutions. It spread culture and raised living standards in many places, but also deepened inequality, strained the environment, and generated significant pushback.
Fiveable's AP World History: Modern Unit 9 review covers 9 topics, with guided practice questions for the unit.
AP World unit 9 topics
Technological Advances and Limitations after 1900: Disease
Poverty-linked diseases like malaria and cholera persisted, emergent epidemics like HIV/AIDS and the 1918 influenza pandemic caused social disruption, and longer lifespans produced new chronic diseases like Alzheimer's.
Technological Advances: Debates about the Environment after 1900
Human activity caused deforestation, desertification, declining air and water quality, and greenhouse gas emissions, generating intense international debates about climate change and resource competition.
Economics in the Global Age
Free-market liberalization accelerated after the Cold War, manufacturing shifted to Asia and Latin America, knowledge economies grew in wealthier regions, and multinational corporations and trade agreements tied the global economy together.
Calls for Reform and Responses after 1900
Rights-based movements challenged assumptions about race, class, gender, and religion, expanding access to voting and education while also protesting the unequal environmental and economic effects of global integration.
Globalized Culture after 1900
Music, film, sports, social media, and consumer brands crossed national borders, creating a shared global popular culture exemplified by K-pop, Bollywood, the FIFA World Cup, and brands like Coca-Cola and McDonald's.
Resistance to Globalization after 1900
Responses to globalization included anti-IMF and anti-World Bank activism, cultural preservation efforts, and the creation of locally controlled alternatives like Weibo in China.
Institutions Developing in a Globalized World
New international organizations including the United Nations, IMF, World Bank, WTO, EU, and ASEAN formed to maintain peace, stabilize the global economy, and facilitate cooperation among states.
Continuity and Change in a Globalized World
Science and technology transformed communication, transportation, agriculture, and medicine after 1900, but older patterns of inequality, social hierarchy, and religious practice showed significant continuity alongside that change.
Practice AP World unit 9 questions
Try AP-style questions on unit 9, then use the review notes below for anything you miss.
AP World unit 9 practice test
A timed, AP-style test built only from unit 9 questions — multiple choice plus free response, scored with AI feedback. Use the standard format or build your own.
Unit 9 review notes
9.1
Technology and Exchange after 1900
After 1900, breakthroughs in communication, transportation, energy, agriculture, and medicine fundamentally changed how people lived and how connected the world became. The key skill here is explaining how specific technologies produced specific changes, not just listing inventions.
- Communication and transportation: Radio, cellular phones, and the internet reduced geographic distance in communication; air travel and shipping containers did the same for goods and people, accelerating global trade.
- Energy technologies: Petroleum and nuclear power raised industrial productivity and increased material goods production, though both created environmental and political tensions.
- Green Revolution: High-yield crop varieties, synthetic fertilizers, and pesticides increased agricultural output and sustained population growth, especially in Asia and Latin America, while spreading chemically intensive farming.
- Medical innovations: Vaccines and antibiotics like penicillin dramatically reduced mortality from infectious diseases and extended average lifespans worldwide.
- Birth control: More effective contraception gave women greater control over fertility, transformed reproductive practices, and contributed to declining birth rates across much of the world.
Can you explain how at least three specific technologies changed human populations or global connections after 1900? Practice linking each technology to a concrete effect.
| Technology | Primary effect | Secondary consequence |
|---|---|---|
| Internet and cellular communication | Reduced geographic distance for information | Enabled global commerce and social movements |
| Shipping containers and air travel | Lowered cost of moving goods and people | Accelerated manufacturing shift to Asia and Latin America |
| Green Revolution agriculture | Increased food production and sustained population growth | Spread chemical-intensive farming and environmental pressure |
| Vaccines and antibiotics | Reduced infectious disease mortality | Contributed to population growth and aging populations |
| Birth control | Gave women reproductive autonomy | Contributed to declining fertility rates in many regions |
9.2
Disease after 1900
Disease patterns after 1900 reflect three overlapping trends: poverty-linked diseases persisted, new epidemic diseases emerged and caused social disruption, and longer lifespans produced new chronic diseases. Medical advances responded to but did not eliminate these challenges.
- Diseases of poverty: Malaria, tuberculosis, and cholera continued to affect populations in the Global South where sanitation and healthcare access remained limited.
- Emergent epidemic diseases: The 1918 influenza pandemic, HIV/AIDS, and Ebola emerged as major threats, causing social disruption and spurring new medical and technological responses.
- Diseases of longevity: As people lived longer due to medical advances, diseases like heart disease and Alzheimer's became more common, reflecting a shift in global health burdens.
- Medical responses: Epidemics accelerated vaccine development, antiretroviral drug research for HIV/AIDS, and international public health cooperation through organizations like the WHO.
Can you sort the AP illustrative examples of disease into the three categories: poverty-linked, emergent epidemic, and longevity-related? Practice explaining why each category matters for human populations.
9.3
Environmental Debates after 1900
Industrialization, population growth, and commercial agriculture put unprecedented pressure on the environment after 1900. The AP exam focuses on causation: human activity caused specific environmental changes, and those changes produced political and social debates.
- Deforestation and desertification: Clearing land for agriculture and industry reduced forest cover and contributed to soil degradation, especially in Sub-Saharan Africa and Latin America.
- Fresh water and air quality: Industrial pollution and agricultural runoff degraded air and water quality, intensifying competition over freshwater resources globally.
- Greenhouse gases and climate change: The release of carbon dioxide and other greenhouse gases from fossil fuels contributed to global warming and sparked ongoing international debates about causes, responsibility, and solutions.
- Environmental activism: Organizations like Greenpeace and movements like Wangari Maathai's Green Belt Movement in Kenya protested environmental degradation and linked it to economic inequality and globalization.
Can you write a causation statement connecting a specific human activity to an environmental change and then to a political or social response? That chain is what the AP exam rewards.
9.4
Economics in the Global Age
The late 20th century saw a major shift toward free-market economic policies worldwide, accelerated by the end of the Cold War. Manufacturing moved to Asia and Latin America while knowledge economies grew in wealthier regions, and new institutions and trade agreements tied the global economy together.
- Economic liberalization: Governments including Reagan's United States, Thatcher's Britain, Deng Xiaoping's China, and Pinochet's Chile reduced state intervention and promoted free-market policies.
- Knowledge economies: Countries like Finland, Japan, and the United States shifted toward economies driven by information technology, services, and intellectual production rather than manufacturing.
- Manufacturing shift: Industrial production moved increasingly to Asia, including the Asian Tiger countries, and Latin America, where labor costs were lower and export-oriented growth strategies took hold.
- Multinational corporations and trade agreements: MNCs like Toyota and McDonald's operated across borders, while agreements like NAFTA and institutions like the WTO formalized free-trade principles globally.
Can you give a specific example of a government that adopted free-market policies and explain what changed in that economy? Can you distinguish a knowledge economy from a manufacturing economy?
| Economy type | Key regions | AP example |
|---|---|---|
| Knowledge economy | United States, Finland, Japan | Growth of information technology and services sectors |
| Manufacturing economy | China, South Korea, Mexico, Brazil | Export-oriented industrial production, Asian Tiger growth |
| Free-market liberalization | United States, United Kingdom, Chile, China | Reagan, Thatcher, Pinochet, Deng Xiaoping policies |
9.5
Calls for Reform after 1900
Rights-based movements after 1900 challenged old assumptions about race, class, gender, and religion. These movements expanded access to education, voting, and professional roles, and they also protested the unequal effects of global integration on marginalized communities.
- UN Universal Declaration of Human Rights: Adopted in 1948, this document asserted universal rights and was used to advocate for the rights of women, children, and refugees globally.
- Women's suffrage and feminist movements: Women gained voting rights across the world in the 20th century, including the United States (1920), Turkey (1934), Japan (1945), and India (1947), alongside global feminist movements challenging gender inequality.
- Negritude movement: An intellectual and cultural movement that challenged racist assumptions about Black identity and asserted pride in African and African diaspora heritage.
- Liberation theology: A theological movement in Latin America that interpreted Christian teachings as a call for social justice and challenged assumptions about class and poverty.
- Environmental and economic protests: Movements like Greenpeace and the Green Belt Movement protested the unequal environmental and economic consequences of global integration, linking social justice to environmental issues.
Can you identify at least two movements that challenged assumptions about different social categories, such as race and gender, and explain what specific change each sought?
9.6
Globalized Culture and Resistance
After 1900, especially in the second half of the century, popular culture and consumer brands crossed national borders at an unprecedented scale. At the same time, many communities pushed back against cultural and economic globalization to protect local identity and sovereignty.
- Global popular culture: Music genres like reggae, hip-hop, and K-pop; film industries like Hollywood and Bollywood; and sports events like the FIFA World Cup and Olympics spread cultural products across borders.
- Global consumer brands: Companies like Toyota, Coca-Cola, and McDonald's, and online platforms like Amazon and Alibaba, created a shared consumer culture that transcended national boundaries.
- Cultural resistance: Some communities resisted cultural homogenization by maintaining local languages, traditions, and media, seeing global culture as a form of cultural imperialism.
- Economic resistance: Anti-IMF and anti-World Bank activism protested the economic terms of global integration, arguing they deepened inequality in the Global South.
- Locally developed alternatives: China's Weibo emerged as a locally controlled social media platform, illustrating how states and communities created alternatives to Western-dominated global platforms.
Can you explain both why culture became more global after 1900 and why that globalization generated resistance? Connecting cause and response is a key AP skill for these topics.
| Form of globalization | Example | Form of resistance |
|---|---|---|
| Global popular culture | Hollywood, K-pop, FIFA World Cup | Preservation of local languages and folk traditions |
| Global consumer brands | McDonald's, Coca-Cola, Amazon | Fair trade movements, local market preferences |
| Western-dominated social media | Facebook, Twitter, Instagram | Weibo in China, state-controlled internet platforms |
| IMF and World Bank economic policies | Structural adjustment programs | Anti-IMF protests, dependency theory critiques |
9.8
International Institutions in a Globalized World
After World War II, states built new international organizations to manage the challenges of a more connected world. The AP exam focuses on how and why globalization changed interactions among states, so the key idea is cooperation through institutions, not the internal details of every organization.
- United Nations: Founded in 1945 with the stated goal of maintaining world peace and facilitating international cooperation, including through the Security Council and the International Court of Justice.
- Bretton Woods institutions: The IMF and World Bank were created at the 1944 Bretton Woods Conference to stabilize the global economy and fund development, though both became targets of anti-globalization criticism.
- Trade institutions: The WTO and earlier GATT formalized rules for international trade, reflecting the spread of free-market principles across the global economy.
- Regional organizations: The EU and ASEAN promoted regional economic integration and political cooperation, showing how globalization reshaped state interactions at a regional level.
Can you explain why states created international institutions after 1945 and give one example of how those institutions changed how states interacted with each other?
9.9
Continuity and Change in a Globalized World
Topic 9.9 asks you to evaluate the extent to which science and technology changed the world from 1900 to the present. This is a continuity and change over time task: you need to weigh what genuinely transformed against what persisted, including older patterns of inequality, social hierarchy, and religious practice.
- Extent of technological change: Communication, transportation, energy, agriculture, and medicine all transformed in ways that reshaped daily life, global trade, and population patterns across the 20th and 21st centuries.
- Persistent inequalities: Despite technological advances, economic inequality between and within nations persisted, and access to new technologies remained uneven, particularly between the Global North and Global South.
- Continuity in social structures: Religious practice, gender hierarchies, and caste systems showed significant continuity even as rights movements challenged them, illustrating that change was uneven and contested.
- Synthesis across Unit 9: Topic 9.9 ties together the unit's themes: technology drove change, but older patterns of power, inequality, and identity shaped how that change was experienced and distributed.
Can you write a thesis that evaluates the extent of change from 1900 to the present? A strong thesis names specific changes, acknowledges continuities, and makes a claim about which was more significant.
Key terms
| Term | Definition |
|---|---|
| Green Revolution | A series of agricultural innovations including high-yield crop varieties, synthetic fertilizers, and pesticides that increased food production and sustained population growth after the mid-20th century, especially in Asia and Latin America. |
| Economic Liberalization | The reduction of government restrictions on markets, including deregulation, lowered tariffs, and privatization, promoted by governments like Reagan's United States, Thatcher's Britain, and Deng Xiaoping's China in the late 20th century. |
| Multinational Corporation | A company that operates production or services across multiple countries, such as Toyota, McDonald's, and Coca-Cola, playing a central role in spreading free-market economic practices globally. |
| Knowledge Economy | An economy driven by information technology, services, and intellectual production rather than manufacturing, exemplified by the United States, Finland, and Japan in the late 20th century. |
| Green Belt Movement | An environmental organization founded in Kenya in 1977 by Wangari Maathai that addressed deforestation through tree planting and linked environmental conservation to social justice and women's empowerment. |
| U.N. Universal Declaration of Human Rights | A 1948 international document asserting universal human rights, used by rights-based movements to advocate for the rights of women, children, and refugees across the globe. |
| Greenhouse Gases | Atmospheric gases, primarily from fossil fuel combustion, that trap heat and contribute to global warming, generating international debates about climate change causes and responsibility after 1900. |
| HIV/AIDS | An emergent epidemic disease that spread globally after the late 20th century, causing significant social disruption and spurring major advances in medical research and international public health cooperation. |
| 1918 influenza pandemic | A major global epidemic that killed tens of millions of people worldwide, illustrating how emergent diseases could cause mass death and social disruption even as medical technology advanced. |
| Negritude movement | An intellectual and cultural movement that challenged racist assumptions about Black identity and asserted pride in African and African diaspora heritage, exemplifying rights-based challenges to racial assumptions after 1900. |
| Liberation theology | A theological movement in Latin America that interpreted Christian teachings as a call for social justice and the liberation of the poor, challenging assumptions about class and religion. |
| NAFTA | The North American Free Trade Agreement, enacted in 1994 among the United States, Canada, and Mexico, which eliminated many trade barriers and exemplified the spread of free-market economic integration in the late 20th century. |
| Consumer Culture | A societal framework in which buying and consuming goods is central to economic and cultural life, which became globalized after 1900 through brands like Coca-Cola, McDonald's, and online platforms like Amazon and Alibaba. |
| Desertification | The process by which fertile land becomes increasingly arid and unproductive, driven by deforestation, unsustainable agriculture, and climate change, intensifying resource competition after 1900. |
| International Monetary Fund (IMF) | An international organization established in 1944 to promote global monetary cooperation and financial stability, which became a target of anti-globalization activism for its structural adjustment policies in the Global South. |
How to review unit 9
Topics students miss most
Miss rates come from Fiveable multiple-choice practice.
Mistakes to avoid in 1900 to Today
Treating globalization as only positive
Students often list technological advances without addressing the unequal distribution of benefits, environmental costs, or the resistance globalization generated. The AP exam rewards arguments that acknowledge both gains and consequences.
Confusing the three disease categories
Malaria and cholera are poverty-linked, not emergent epidemics. HIV/AIDS and the 1918 influenza pandemic are emergent epidemics. Heart disease and Alzheimer's are diseases of longevity. Mixing these up weakens evidence in free-response answers.
Listing free-market leaders without explaining the policy
Naming Reagan, Thatcher, Deng Xiaoping, and Pinochet is not enough. You need to explain what free-market liberalization actually meant, such as deregulation, reduced tariffs, and privatization, and what changed as a result.
Describing cultural globalization without explaining causation
Saying K-pop and Bollywood are global is a description, not an explanation. The AP exam asks why culture became more global, which requires connecting specific technologies like the internet and satellite television to the spread of cultural products.
Treating Topic 9.9 as a summary rather than an argument
Topic 9.9 is a continuity and change over time task. Simply restating what changed in Unit 9 is not enough. You need to evaluate the extent of change by weighing transformations against persistent patterns and making a defensible claim.
1900 to Today on the AP exam
Causation questions on technology and environment
Unit 9 content appears frequently in causation tasks asking you to explain how specific technologies or human activities produced specific changes in populations, economies, or the environment. Practice writing causation statements that name a mechanism, not just a correlation, such as explaining how shipping containers lowered trade costs and accelerated manufacturing shifts to Asia.
Continuity and change over time arguments
Topic 9.9 is explicitly a continuity and change over time task, and that reasoning skill runs through the entire unit. Free-response questions may ask you to evaluate the extent to which globalization transformed economies, cultures, or social structures from 1900 to the present. Strong responses name specific changes, acknowledge what persisted, and make a claim about relative significance.
Comparison across regions and time periods
Unit 9 connects to earlier units, and comparison tasks may ask you to link globalization patterns to earlier trade networks from Unit 2, industrialization from Unit 6, or decolonization from Unit 8. You may also be asked to compare how different regions, such as knowledge economies versus manufacturing economies, or the Global North versus the Global South, experienced globalization differently.
Study unit 9 other ways
- Topic study guides
- Practice questions
- FRQ practice
- Cram archive videos
- Official unit cheatsheet
- Score calculator
Unit 9 printables
Print the unit cheatsheets ($3) for Unit 9. Yours to keep, no subscription needed.
get printablesFrequently Asked Questions
What's on the AP World Unit 9 progress check (MCQ and FRQ)?
The AP World Unit 9 progress check includes MCQ and FRQ parts that test globalization content from 1900 to the present. The MCQ section draws on topics like advances in technology and exchange, economics in the global age, globalized culture, and resistance to globalization. The FRQ part typically asks you to analyze continuity and change or causation across those same themes. For matched practice questions that mirror the progress check format, visit /ap-world/unit-9.
How do I practice AP World Unit 9 FRQs?
AP World Unit 9 FRQs most often focus on globalization themes like resistance to globalization, calls for reform and responses, and continuity and change in a globalized world. The question types you'll see are SAQ (short-answer), LEQ (long-essay), and DBQ (document-based question), all asking you to argue causation or continuity and change. To practice, write timed responses using specific evidence from topics 9.1-9.9, then check your thesis and evidence against the College Board rubric. Find practice prompts and study guides at /ap-world/unit-9.
How should I study AP World Unit 9?
Start studying AP World Unit 9 by building a timeline of globalization from 1900 to the present, anchoring key events to each topic. Focus first on advances in technology and exchange (9.1) and economics in the global age (9.4) since those underpin almost every other topic. Then work through calls for reform and responses (9.5), resistance to globalization (9.7), and debates about the environment (9.3), because those show up most often in FRQ prompts asking for causation or continuity and change. After reading, do a short MCQ set to check retention, then write one timed SAQ or LEQ using specific evidence. Repeat that read-quiz-write cycle for each topic. Find guides and practice sets at /ap-world/unit-9.