It is, as others have stated, a fantasy. The
amero is as yet an entirely hypothetical future currency for an as-yet entirely hypothetical monetary union. Actual physical amero coins are decades away at best; it took the Europeans over ten years to create the euro and I don't think North American bureaucrats are that much more efficient than their European counterparts.
As the Wikipedia article states, the amero hit the news some years ago when Daniel Carr made his own amero fantasy patterns. You can read about those in
this old forum thread and others; just do a forum search for "amero" to find them.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis