In a horticultural society, hand tools are used to tend crops. The first horticultural societies sprang up about 10,000–12,000 years ago in the most fertile areas of the Middle East, Latin America, and Asia. The tools they used were simple: sticks or hoe-like instruments used to punch holes in the ground so that crops could be planted. With the advent of horticultural machinery, people no longer had to depend on the gathering of edible plants—they could now grow their own food. They no longer had to leave an area when the food supply was exhausted, as they could stay in one place until the soil was depleted.
A pastoral society relies on the domestication and breeding of animals for food. Some geographic regions, such as the desert regions of North Africa, cannot support crops, so these societies learned how to domesticate and breed animals. The members of a pastoral society must move only when the grazing land ceases to be usable. Many pastoral societies still exist in Africa, Latin America, and parts of Asia.
The invention of the plow during the horticultural and pastoral societies is considered the second social revolution, and it led to the establishment of agricultural societies approximately five thousand to six thousand years ago. Members of an agricultural or agrariansociety tend crops with an animal harnessed to a plow. The use of animals to pull a plow eventually led to the creation of cities and formed the basic structure of most modern societies.
The development of agricultural societies followed this general sequence: