Early in human history, people discovered that they could stir up soil, drop seeds in the stirred up soil, and cause the earth to produce edible vegetation, instead of going out searching for wild vegetation to eat. The tool that was first used to stir up the soil was probably a simple stick. But however simple it might have been, it was the first plow. Sometime in the early Bronze Age plows began to be made of soft metal. Later, cast-iron was used. And then in the eighteenth century, a device was invented that was to change the world: the moldboard plow.
