The dotted line indicates where the dollar was detached from gold.
One the most important things about gold as a monetary foundation is that it forces financiers and economists to deal with reality. Gold is the North Star by which economies and currencies are judged. It’s been this way for millennia, and it likely will remain the case for many years to come. But we have detached our money from gold, and reality. In 1971 Richard Nixon severed the last ties the dollar had to gold.