20 Balboas A Century Uniting the World

Panama's centennial commemorative program has produced some genuinely overcrowded designs, but this issue marks the 2016 centenary of the Canal's formal opening to commercial traffic — an engineering project that killed an estimated 25,000 workers during the French phase alone, before the United States resumed construction in 1904. The balboa denomination itself was pegged one-to-one with the U.S. dollar at inception and has never floated independently.

The .9999 fineness is notably purer than the traditional .925 standard for commemorative silver, a deliberate specification choice by the issuing authority.