How did the American dollar sign ($) and British pound sign come about?

Question

and/or what do they mean?

Answer 1

If you nate carefully the American dollar sign has two vertical bars, it actually is a "U" superimposed on top of the "S", for U.S. I don't know anything about the British poound symbol.

Answer 2

the British pound sign is a descendant of the roman abbreviation for the roman unit of currency, before decimalization, pounds , shillings and pence was abbreviates L,S,D to reflect the Roman coinage system