Take the Central American transcontinental railroad
Opened in 1855, the Panama Canal Railway was the first railroad to cross from one ocean to another and had a big part to play in the California Gold Rush as well as in the eventual construction of the Panama Canal. Until the canal opened in 1914, it carried more freight relative to its length than any other railway in the world.
The service still runs today, connecting Balboa on the Pacific side of Panama to Colón on the Caribbean – a journey of just 77km that spans a continent.