The origin of the word dollar comes from the coins that Spanish emperor Carlos I ordered to coin at the beginnings of the XVIth century. They were of silver, (read Webster's wu for more precise information) and they had the same value as the German thaler.

A century later, when the spanish thalers began to circulate in North America, they were called spanish dollars, as someone wrote "dollars" instead of "thalers".

When the U.S.A. became a nation, the dollar acquired the category of national currency. In those coins were engraved the Columns of Hercules, the symbol for the Spanish Empire, that ultimately were converted into the sign that epitomizes dollars and money everywhere: