Chocolate is made from cacao beans, the seeds from the Theobroma cacao tree, which grows close to the equator worldwide. The naturally bitter seeds are fermented, dried, roasted and crushed to make cocoa nibs, the foundation for chocolate. The nibs are then pureed with sugar and cocoa butter (the fat that emerges when the cacao beans are processed) and liquefied. At that point, the liquid chocolate undergoes a process known as tempering, which entails raising and lowering the temperature, resulting in a distinctively smooth, solid and crisp texture upon cooling.
Chocolate has existed in the New World since at least 600 BC and was treated largely like a spice at the time. When Cortez came to Mexico in 1519, he noticed the popularity of chocolate as a drink, either sweetened (by the upper classes) or thickened with cornmeal (by the lower). He took it back to Europe and the sweetened version became immensely popular with the upper classes. The refining and production became more and more extensive and widespread over the next few centuries; in 1819 a Swiss manufacturer invented what is thought to be the first chocolate bar.
Cocoa powder followed shortly thereafter with the invention of the cocoa press in 1828. Milk chocolate bars were produced 30 years later and chocolate consumption took off in leaps and bounds. The average American now consumes over 12 pounds of chocolate per year.