In 1513, the Spanish explorer Vasco Núñez de Balboa had to sail across the Atlantic, land in what is now Panama, then trek through jungles and over mountains before seeing another vast ocean—the Pacific. The advantages of linking them were obvious, but it was another 401 years before technology caught up with geography. In 1914, the newly built, fifty-mile-long, American-controlled Panama Canal opened, thus saving ships an eight-thousand-mile journey from the Atlantic to the Pacific Ocean
