Tampico (tämpēˈkō) [key], city (1990 pop. 272,690), Tamaulipas state, E Mexico, on the Pánuco River, a few miles inland from the Gulf of Mexico. Rivaling Veracruz as Mexico's most important seaport, Tampico is used primarily for Mexico's petroleum industry. It possesses excellent modern facilities and also serves as an export center for Tamaulipas state's other goods, including cattle, hides, sugar, and additional agricultural products. In pre-Columbian times, Tampico was the site of the Huastec kingdom, which later became a tributary of the Aztec Empire. Spanish settlement dates back to the founding of a Franciscan mission there in the 1530s. Tampico was occupied by a U.S. force during the Mexican War and by French troops in 1862, during the French intervention. With the discovery of oil (c.1900) by English and American geologists, rapid development of petroleum industries began; before Mexico expropriated foreign-owned property, about one third of Tampico's landowners were Americans. The city boomed while much of the rest of Mexico was in revolutionary turmoil. Tampico is the seat of a state university and an active cultural center.