Like many kids, I was taught about money and that it “doesn’t grow on trees”. Because dad’s hobby was numismatics, the collecting of monetary objects, I received thumbnail histories of the major forms of money. I think I was seven or eight years old when I began earning an allowance. That was when dad gave me a short history about the U.S. dollar.
I wondered where the name, dollar, came from. He said the word is the English
“dollar” used during colonial times
translation of the word “Thaler” (pronounced tah-lur). Thaler is an abbreviation of the word “Joachimsthaler”, which is the German word which means somebody who lives in Joachimsthal. Thalers were the type of currency used in the Austro-Hungarian Empire and in Prussia until the mid-1800s.
Dad is proud of our Scandinavian ancestry, so he felt compelled to mention how Danes, Norwegians, and Swedes used their own form of currency called the “Daler”. In Sweden, their Daler was used since 1534.
first US silver dollar
The English form of the word “dollar” was first used as a general shorthand term when refering to coins from various European regions. This is especially true for Spanish Pesos and Portuguese pieces of eight. Spanish money had been in wide use in much of North America for many years before the English corporations began colonizing the area. Then, during the American Revolutionary war, Spanish money again was often used in deference to using British money. 
In the 1780s, the new United States decided to choose the dollar, based on the decimal system because of its simplicity compared to the English Pound system. On July 6, 1785, the dollar was unanimously, officially selected as the unit of money for the United States. Several years later, Congress passed the Coinage Act of 1792. Among other things, it authorized the first U.S. Mint in the then capital city of Philadelphia. The first Secretary of the Treasury, Alexander Hamilton, 
recommended to Congress the system of our monetary denominations.
Thus began the long, and often controversial, history of the U.S. Dollar.
Ciao
The Blue Jay of Happiness relates one story about the origin of the $ sign. If you superimpose a capital U onto a capital S, then erase the lower curve of the U, you get the version of the $ symbol with two vertical lines. It’s shorthand for the US.
