Ten thousand Frenchmen died of various tropical diseases in an effort to build a Panama canal. The French effort ended ten years prior to the start of the American work. The Americans solved two problems that stymied the French: mosquitoes (they carried the diseases) and where to put the dirt (it kept getting in the way). The mosquito problem was solved by spraying a mist of petroleum onto every water surface in the country from lakes to tiny puddles below downspouts. The dirt / spoils problem was solved by Chief engineer of the Canal project, former railroad engineer, John F. Stevens who spent the first year of his tenure in Panama, to the mystification of his supporters back home, building a railroad into the Panama hinterlands. It was rail cars that carried away the dirt and rock thus making the entire project feasible.