The 50-mile Panama Canal was a multi-national, multi-decade project to link two oceans and transform global shipping. After completion in 1914, the canal helped turn the United States into an economic juggernaut.

President Donald Trump has called for the US to retake control of the Panama Canal unless the cost of passage for naval and merchant ships is slashed. Trump’s refusal to rule out the use of force is a throwback to the 19th century era of gunboat diplomacy.