height as a port city in the 19th century. At the beginning of this century, French, German and Italian immigrants came to the area to plant and weave cotton, to be sold in English markets. Starting in 1821, Tlacotalpan experienced economic grown as a port for products from Oaxaca and Puebla going to Veracruz and abroad to New Orleans, Havana and Bordeaux. By 1855 it was home to eighteen steamships and a large sailing ship which transported timber, tobacco, cotton, grain, sugar, brandy, leather, salted meat, crocodiles, heron feathers, furniture and soap. In 1825 one of Mexico's first nautical colleges was opened, founded by Guadalupe Victoria. In 1847, Tlacotalpan was officially declared a town in recognition of its participation in the defense against U.S. forces in the Mexican–American War. In 1864 the town was taken by French forces under Marechal one day after taking Alvarado. Later that same year, Republican forces under Alejandro García retook the area. In 1865 it was declared a city and provisional capital for its resistance against the French. In 1879, Miguel Z. Cházaro founded Veracruz's third preparatory school. Here Porfirio Díaz organized an uprising against the government of Sebastián Lerdo de Tejada, which led to a name change of Tlacotalpan de Porfirio Díaz in 1896. This was changed to the current version after the Mexican Revolution. At the beginning of the 20th century, the town had eight schools, three hotels, nine factories and 100 single-storied houses. However, in the first part of the 20th century, Tlacotalpan's importance as a port, which had sustained it since the colonial period, waned with the construction of the Ferrocarril del Istmo railroad. Its population grew only slightly from 1950 to 1980 and has remained stable since then at a bit over 8,800. In 1968, conservation efforts began when Tlacotalpan was declared a "typical city" of Mexico by the state of Veracruz. In 1986 it was declared a Historic Monuments Zone by the federal government to be managed by the Instituto Nacional de Antropologia e Historia (INAH) and the Instituto Nacional de Bellas Artes (INBA). In 1985 and 1997 a transition zone was established which includes areas across the river which serves as a buffer to the main conservation area. In 1998, it was named a World Heritage Site by UNESCO for its history as a river port, its architecture and its traditions in poetry, music and dance. Since these