The Mayab and Chiapas lines, now part of the FIT were formerly leased to Ferrocarriles Chiapas-Mayab until Genesee & Wyoming gave up its concession in 2007.

[3][4][5] More serious planning began in the early 1840s, when José de Garay, the First Officer of the Ministry of War obtained a concession on the route and carried out a more thorough survey.

The opening of the Panama Railroad in 1854 provided competition for the Tehuantepec route, but also gave warning that the TRNCO's cost estimates were wildly optimistic.

[7] In spite of this, the company managed to construct a wagon trail (not a railroad) along the route, and offer a service for passengers and mail from New Orleans to San Francisco, starting in 1858.

The outbreak of the American Civil War and the French intervention in Mexico the following year ended any immediate hope of reviving the project.

[9] No government action resulted, however, and actual canal construction was started in Panama in 1881 by a French company headed by Ferdinand de Lesseps.

[10] Eads' ideas received considerable support in the USA, but he died in 1887, and this was effectively the end of the proposal.

It soon became clear that a complete overhaul was necessary, and Weetman D. Pearson was contracted by the Mexican Government to undertake the work.

The railroad continued to handle substantial passenger traffic well into the fifties, but ceased to be a significant carrier of freight.

[12][9] On 7 June 2020, President of Mexico Andrés Manuel López Obrador announced the beginning of the rehabilitation of the line.

[30] The Medias Aguas-Salina Cruz section of the passenger railway performed its first tests in September 2023, including an official trip by the President and his staff, and the director of the CIIT, vice admiral Raymundo Morales Ángeles, stated that it will begin passenger operation in December, though cargo operations did officially begin in September.

[41][42] In addition, the Mexican government bought 12 special wagons (including three Amfleet coaches) from the Railway Excursion Management Company (Railexco).