There is a long history of attempts to build a canal across Nicaragua to connect the Atlantic Ocean with the Pacific Ocean. Construction of such a shipping route—using the San Juan River as an access route to Lake Nicaragua—was first proposed in the early colonial era. Napoleon III wrote an article about its feasibility in the middle of the 19th century. The United States abandoned plans to construct a waterway in Nicaragua in the early 20th century after it purchased the French interests in the Panama Canal. The Panama Canal was built and that is now the main connecting route across Central America.