[2] In 1868 the "Ferrocarril de Chalco" opened a second street railway to Tacubaya along Avenida Chapultepec.
[3] The Ferrocarril de Tacubaya opened a second line to Popotla, near the Calzada México-Tacuba (Tacuba causeway).
[2] The Compañía de Ferrocarriles del Distrito Federal, organized in 1878, began to install lines for animal-powered street railways including one in the Calzada de Tlalpan (Tlalpan Causeway),[3] and controlled street railway lines until 1901.
[3] Lines ran north as far as Tlalnepantla, as far south as Tlalpan, as far east as Peñón de los Baños.
[3] In 1896 the then-municipal government of Mexico City (the Ayuntamiento de México) authorized the Federal District Railways to change from animal to electric power.
[4] Animal-powered street railways would continue to operate in the city along with electric streetcars for another thirty years.