E. Modern History since the French, American and Industrial revolutions of the late 18th century. These definitions are very much centered on Europe. They do not apply to other parts of the world very well. They also tend to represent the politics and arts of the elite in society. In practical terms they have something to do with the amount of source material that survive.
Modern historians have to select sources from a assive amount of material.
Ancient and Medieval historians have to work hard to fill in the gaps between the sources. The Agricultural Revolution One of great developments in human history, Only the Industrial Revolution is comparable. Food producing, not food gathering. Llamas Half current calories in world from Amerindian domesticated crops. B. Reasons for Agricultural Revolution.