"Three changes transformed the way humans lived."

People don’t have to live in states and there’s no rule that states must have cities. People in states and cities do not need to be farmers themselves or trade with others in farming-based places. But, these four things usually happen together. This unit will explore why and how they are connected.

There are many reasons why the history we study tends to focus on agrarian cities and states. History is usually written by people in cities and states that are centers of farming and trade. Those cities and states are places where people exchange ideas and create, so they often seem like important historical centers.

However, a lot happened during the period we’re covering in Unit 3—and even after—in societies that weren’t states or cities, didn’t farm, and weren’t trade centers. We’re going to learn about some of these societies too. But, because changes in these societies were usually slower, we’re going to focus more on how trade grew, cities developed, and states formed. These changes really shaped how humans live, connect, and create.

Village networks

By 6000 BCE, humans had spread from Africa across most continents and islands. Some communities began farming and raising animals, while others continued gathering and hunting. These groups adapted to their surroundings, developing unique strategies and tools.

Innovation was often spurred by environmental changes or through exchanges with other societies. New methods, ideas, and tools typically originated in one place. Then, they spread to other societies through trade, conflicts, and intermarriage. When societies interacted, they frequently adopted or modified these innovations to fit their needs. Major inventions in human history—like iron and boba tea—originated just a few times. They then traveled through networks globally as different groups adopted and enjoyed them.

During this era, local networks were crucial for survival. Agricultural villages and nomadic tribes formed connections. Each group specialized in specific products to trade for other goods. This exploration of community types and their trade and interaction networks highlights the complexity of early human societies.

Long-distance trade

Trade networks began locally but expanded significantly over time. Across the globe, these networks facilitated the movement of goods, people, and ideas. With the emergence of cities, metropolitan networks formed, linking cities to their surrounding villages and rural areas. These cities had some level of control over these areas due to their larger populations.

As a result, trade networks grew even more extensive. In Eurasia, the domestication of horses enabled faster communication. Rulers could extend their influence to further regions from their empire’s capitals. Similarly, the introduction of camels in western Asia and Africa revolutionized travel across deserts, increasing the rate at which people and goods could move. In the Americas, llamas played a comparable role, aiding in the transportation across various terrains.

At sea, better ways to build ships and navigate expanded trade to far places. In areas like the Caribbean, the Mediterranean, and the Baltic seas—and later the Pacific Ocean—large networks of trade relied on skilled shipbuilders and sailors. On land, advances in technology also played a role. Infrastructure projects like road construction made connections more efficient. As a result, travel increased. Although the number of travelers was small compared to the total population, those who traveled learned different languages, encountered fresh ideas, and shared those concepts in new locations.

Cities

Cities and trade have a “which came first, the chicken or the egg?” situation. Cities often began around markets where traders from various places met. But, as cities grew, they boosted trade since city dwellers had surplus items like money and food. They sought luxury items to improve their lives.

The earliest cities might have emerged in Anatolia, Mesopotamia, and Egypt, around 6,000 years ago. In regions like China, India, and Southeast Asia, cities formed about 5,000 years ago. Later, from 4,000 to 2,500 years ago, new cities developed in Mesoamerica, the Andes, the Mediterranean, and sub-Saharan Africa.

Cities were established for several reasons. Some benefited from trade routes, others were built for defense, some for religious gatherings, and others as government hubs. These cities were part of farming societies, where agriculture produced a surplus of food. This surplus supported soldiers, priests, builders, and specialists needed in cities. Yet, each society or city, like Shang Dynasty China, Nubia, or Mesopotamia, had its unique structure and lifestyle.

One thing these societies all shared was a group of wealthy people. Usually, this group was small, and the majority of people in the cities were poor in comparison. The majority of people worked hard and often got sick because of the crowded conditions in cities, where people, animals, and waste were all close together.

States

Long-distance trade made a small group of people very rich. These “elite” people had special rights and power because they controlled money and resources. To keep their special rights safe, elites started to build the state. This included making rules, laws, government buildings, and armies that protected everyone, but especially the rich ones. In their chase for more power and wealth, elites could push states to start violence and wars bigger than any seen before in human societies.

The rise of the state was closely connected to the development of writing. And writing was probably the most important development during this era. The ability to read and write was rare and generally something only the wealthy had. Therefore, writing deepened the distance between elites and commoners. The first written texts weren’t love poems or novels; they were inventories and receipts for things people owned and traded. Writing started as a way to record the trading of goods and surpluses of food. Writing allowed a merchant to record that they had traded three goats for five bushels of wheat. It let rulers write down instructions to the commanders and governors overseeing the furthest edges of their states.

Still, not all states were the same, as we will see. Assyria, in Mesopotamia, had a hierarchical structure. It was quite different from the negotiated power of Jenne-Jeno, in West Africa. Instead of a ruling elite, different groups split power in Jenne-Jeno. The Olmec cities of Mesoamerica had decentralized rule by religious leaders. This was a big difference from the centralized power of Akkadian kings in Mesopotamia.

Despite all the connections that developed during this period, human societies remained quite diverse. In fact, the wide range of economies, social structures, and cultures in this period helps remind us of the shared creativity that is a human trait. There’s no single pathway for human societies. Each is a product of trade and exchange mixed with local ideas and the genius of individuals. Ancient societies unleashed that genius in ways that made for unique communities while contributing to a shared human history.