Long before Pepsi and Coke, even long before coffee, there was once a source of enough caffeine to make you jittery, or even to make you throw up, in the biggest city in North America.
In 1100 A.D., the biggest city in North America was near present-day St. Louis. Scientists don't know what the locals called it then, but now we know it as Greater Cahokia, a metro area that some say might have had many as 30,000 to 50,000 people. In its time, it was bigger than London, then groping its way out of the Dark Ages.
The drink was, and is, black, and it is called the Black Drink.
"Coffee and tea had better marketing," says Thomas E. Emerson, the director of the Prairie Research Institute's Illinois State Archeological Survey.
"Drink the, um ... Black Drink!" just didn't catch on as advertising slogan.
Europeans did try the black drink, and liked it ... a little. It hung on in the American Southeast. During the Civil War, when supplies were scarce, chicory covered for coffee, and the black drink had a resurgence of interest.
Some remnant groups in the Southeast still drink it.
The black drink is made from the leaves and sometimes the twigs of a holly native to Florida and its neighbors.
Its Latin name is Ilex vomitoria.
There's vomit in the name because, when Spanish, French and English explorers came here more than 200 years after the decline of Cahokia, American Indians were still drinking the stuff by the gallon, quite literally.
Emerson says they drank again and again from quart-sized seashells until the hot liquid refused to stay down. The practice in later American Indians seems to have been part of a purification and cleansing ceremony.
But others just drank it because they liked it, he added.
In old Cahokia, Emerson and his co-authors have proved that the black drink was consumed in clay beakers, pots with a handle on one side and a lip on the other.
Using the beakers, Emerson worked with chemists and even chocolate experts on the research, with co-authors at the University of Illinois, the University of New Mexico, Millsaps College in Mississippi and Hershey Technical Center in Pennsylvania.
They found traces of three chemicals — theobromine, caffeine and ursolic acid — in the proper proportions on baked clay dating back to the height of Cahokia culture nearly 1,000 years ago.
The testing process was only used on a few vessels, Emerson says, because destruction is intrinsic to it.
"Very few museums would say, 'Please, grind up our artifacts,'" he says.
One of the reasons the research is so striking is because there has long been evidence that Cahokia and other mound cities traded with each other, but that evidence was durable: shells, bones, jewelry items.
But tea leaves don't last very long in the soil. Twigs last a little longer.
Since the holly doesn't seem to grow in the American Bottom, or even a few hundred miles from it, Emerson's team is thinking a lot about if it was imported as dried leaves or entire bushes. It had to have come from the Southeast.
A smaller and later Mississippian culture in Oklahoma might also have been part of the widespread black drink traffic.
Greater Cahokia was a crossroads of trade, Emerson says. It's near the juncture where the nation's biggest river, the Mississippi, meets the mighty Missouri — and not far from where the Illinois drains into the big river.
The residue is the first known use, by several centuries, of the drink in North America. Other cultures in the Americas have similar brews, such as mat.
But if you decide you want to purify yourself by vomiting, there's only one beverage for you.
Drink Black Drink!