Thanks to bodegas, tax-dodging bars, and street vendors, cash has been successfully fending off extinction for quite some time. But now that Tim Cook and Apple have decided to wage war on our nation's payment systems—as well as other fresh card technologies—cash might only be used by people who need a stable untraceable currency (shoutout to Bitcoin!).
It'll be a shame if it vanishes, because cash has a history of cool designs that reflect the times. Looking back on the cash of yesteryear, it's clear that we've been in a decline for a while. The largest denomination you can get these days is the $100, which is pretty boring.