Core question
How did long-distance trade connect societies and change them? Track goods, technology, belief systems, diseases, and state power.
AP World History Modern
Unit 2: Networks of Exchange
Trade routes, commercial technology, cultural diffusion, environmental effects, and disease across Afro-Eurasia.
01
Big Picture
Three networks
Know Silk Roads, Indian Ocean trade, and trans-Saharan trade as separate systems with different geography and transport methods.
Best writing habit
Use a chain: demand for goods led to more trade, which encouraged cities, credit systems, state support, and cultural diffusion.
02
Silk Roads
What moved
Luxury goods such as silk, porcelain, spices, horses, and textiles moved across caravan routes.
Why it grew
Mongol rule increased safety across Eurasia, making travel and trade easier during the Pax Mongolica.
Cultural diffusion
Buddhism, Islam, technologies, artistic styles, and knowledge moved with merchants, monks, diplomats, and travelers.
03
Indian Ocean Trade
Technology
Monsoon winds, the lateen sail, sternpost rudder, astrolabe, and dhows helped merchants cross open water more predictably.
Trade pattern
This network moved bulk goods more efficiently than overland routes because ships could carry more than pack animals.
Swahili Coast
East African port cities connected African gold, ivory, and enslaved people with Asian textiles, ceramics, and spices.
04
Trans-Saharan Trade
Main goods
Gold, salt, enslaved people, and manufactured goods moved across the Sahara using camel caravans.
State growth
Ghana, Mali, and Songhai benefited from taxing and controlling trade routes.
Islam
Islam spread through merchants, scholars, and rulers, especially in cities and elite circles, while many local practices continued.
05
The Mongol Empire
State impact
The Mongols built the largest contiguous land empire and connected trade routes across Eurasia.
Continuity and change
They often adapted local administrative practices while changing who held political power.
Disease
The same connections that moved goods and ideas also helped the Black Death spread.
06
Travelers and Evidence
Marco Polo
European traveler whose accounts described Yuan China and helped shape European curiosity about Asian wealth.
Ibn Battuta
Muslim traveler whose journeys show the reach and diversity of Dar al-Islam.
Historical caution
Travel accounts are useful evidence, but they reflect the writer's perspective and should not be treated as perfectly neutral.
07
How to Write About Unit 2
Causation model
Increased demand for luxury goods encouraged the growth of trade cities, commercial tools, and state support for routes.
Comparison model
The Indian Ocean carried more bulk goods by ship, while the Silk Roads focused more on luxury goods because caravan transport was expensive.
Common mistake
Do not say trade only moved goods. Strong answers include ideas, religions, technologies, people, crops, and diseases.