Indigo is the deep blue dye that organized plantation systems across three continents, sparked one of the earliest mass resistance movements in colonial South Asia, and then vanished from the fields within a decade when synthetic chemistry made the natural plant obsolete — only to reappear as the color of blue jeans, the most democratic garment in the world.
Pull a pair of blue jeans from your drawer and you are holding the afterlife of one of history's most coerced crops. Indigo blue comes from a plant. In several of its most profitable colonial forms that plant was grown by people with little or no choice: enslaved workers on Caribbean islands, and bonded farmers in Bengal forced by British planters to plant indigo instead of food. In 1897 a German chemical company synthesized the color in a factory, and within a few years the dominant natural-indigo export economy collapsed, above all in Bengal. The blue did not disappear. It got cheaper. It dyed the denim that clothed miners and laborers, and eventually became the color everyone wears. A dye so valuable that empires coerced vast numbers of people to make it is now so ordinary that you probably own several items colored by its synthetic twin.