A mining hole in the mountains of Bohemia produced so much silver it became the official source of coinage for the entire Holy Roman Empire. The mine was in a valley called Joachimsthal, and the coins came to have the same name: “Joachimstalers.” Over time this became shortened to “Talers” and over more time, the American pronunciation of the word became the name for the currency that you would like to have in your pocket.
The $ sign was designed in 1788 by Oliver Pollock, a New Orleans businessman, using a combination of Spanish money symbols.