The concept of an overland route from one tip of the Americas to the other was originally proposed as a railroad at the First Pan-American Conference in 1889; however, this proposal was never realized. The concept of building a highway emerged at the Fifth International Conference of American States in 1923, after the automobile and other vehicles had begun to replace railroads for both passenger and goods transportation. The first conference regarding construction of the highway occurred on October 5, 1925.