Modernización sobre Rieles. El Ferrocarril de Barranquilla y el Tranvía Eléctrico de Medellín. Dos Obras de Gran Impacto en el Proceso de Construcción de Ciudad: 1870-1955

this article analyzes the impact of tow devices modernizing mass transit, tram and railway medellin barranquilla. discusses their construction and consolidation processes as transportation system and their effect on the process of building modern city in medellin and barranquilla respectively. similarly, we examine its operation as business projects and the different circumstances that led him to be the axis of the road system in their respective localitiesand crises that ultimately produce its decline and closure. it also discusses the historical, economic and social of the two urban centers, due to different experiences and commercial, industrial and cultural center of the colombian nation in the first half twentieth century.