Yes they are backed by the U.S. Government, the most powerful organization in the history of world civilization. They are a representation of a claim on wealth

Yes they are backed by the U.S. Government, the most powerful organization in the history of world civilization. They are a representation of a claim on wealth by the entity that holds a monopoly on the legal use of violence to compel people to accept said currency as a medium of exchange. So, like, pretty much what I am looking for when I need to buy stuff.