Often called one of the seven modern wonders of the world, the Panama Canal splits the continents of North and South America and launched a new era in global commerce when it opened in 1914.

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.

They say they fought too hard to wrest it from the U.S. to now hand back the waterway, which is part of the nation’s identity.