While Federal notes, or Euros for that matter, might be appropriate for a merchant to use across state or national boundaries, local currencies make for greater fluidity and accountability between members of the same community.
Accrescunt teneris tactu nova robora nervis: Consuetus fulcro innixus reptare bacilli Nunc saltu capreas, nunc cursu provocat euros.
strand I come, where erst we disembark'd, Still giddy from the roll of ocean's billowy surge, Which, through Poseidon's favor and through Euros' might, On lofty crested backs hither hath wafted us, From Phrygia's open field, to our ancestral bays.
Caeruleus pluviam denuntiat, igneus Euros.
In the course of this development the expanding Roman Empire grew to be the wealthiest and most powerful political, sociological and cultural unit in the Euro-Asian-African area.