On passage from the Pacific to Atlantic side, Jonny Dymond (BBC Washington DC correspondent) explores how digging the so-called "Big Ditch" across the narrow isthmus at Panama changed the world.
In this first episode of two he evaluates how, a century ago when it was constructed, the canal marked the birth of a new global superpower, the United States of America. To what extent did the canal ensure its economic and military dominance?
Today, however, China's influence grows in Central America, a region traditionally America's backyard. What plans are afoot for Chinese-backed alternative routes across the isthmus to rival Panama's?
Tracing these developments, as well as other strands in this fascinating tale, Dymond investigates how the tiny nation of Panama, and the rather small waterway that bisects it, contains a rather large slice of world history.
The success story belongs to the States, but how did they pull off this extraordinary feat of engineering where many had failed? In the shady past lay the broken dreams and appalling costs of, first, the catastrophic French attempt that consumed the lives of tens of thousands of men and, centuries before, the failed projects of the Spanish Conquistadors and even the bankrupted Kingdom of Scotland.
Moving forward, as Panama improves the canal in an impressive $5bn expansion project, what will happen to the patterns of world trade? And what of China's plans and other trade routes?
Global economics and strategic geopolitics are all reflected in what happens on the canal.
Producer: Dom Byrne
A Blakeway production for BBC Radio 4.