sentences:  Conflicts have even led to the formation of armed groups such as the Ejercito Popular Revolucionario in the latter 20th century.Despite brokered talks and disarming, the region is conflictive, especially along the Hidalgo/Veracruz border.The major development of the 20th century in the Huasteca was the development of roadways and other infrastructure to connect it with the rest of the country.