Did you know that salt has been used by humans for over thousands of years? Its ability to preserve foods, especially meats, was a foundation of civilization. When food was preserved with salt, it allowed it to keep while traveling over long distances. However back then, salt was difficult to obtain, so it was considered a highly valued trade item. It has even played a key role in economic, political, and social development. Some countries even used salt as a currency! Today salt is easily obtainable and relatively inexpensive.