Can you hand me the salt?

The salt trade was based on one fact — it is more profitable to sell salted foodstuffs than to sell just salt. Thus sources of food to salt went hand in hand with salt making. The British controlled saltworks in the Bahamas and North American cod, their sphere of influence quickly covered the world. The search for oil in the late 1800s and early 1900s used the technology and methods pioneered by salt miners, even to the degree that they looked for oil where salt domes were located.