Which silver coin became the main trade currency of the Spanish Empire in the Americas?

The Spanish dollar became the main trade currency of the Spanish Empire in the Americas.

Also called the piece of eight or eight-real coin, the Spanish dollar was minted from high-quality silver produced in the Americas. Major mints included Mexico City, Lima, Potosí, and Bogotá. Its consistent silver content made it trusted in long-distance trade across the Atlantic and Pacific.

Spanish dollars circulated widely in North America, Europe, Asia, and the Caribbean. In the early United States, the dollar was defined partly with reference to the familiar Spanish dollar, which remained legal tender until 1857.

The coin is sometimes confused with the Mexican peso because Mexico continued the Spanish dollar tradition after independence. The term “Spanish dollar” refers to the imperial coinage, while later pesos were successor currencies. Its widespread use also helped inspire the dollar sign and the design of several modern currencies.