Mexico straddles the southern part of North America, with coastal plains along the Pacific and Atlantic coasts rising to a central plateau. Northern Mexico is desert-like, while the south is a mountainous jungle containing Maya and Aztec ruins. Most people live in the densely populated waist of the country, including the cities of Veracruz, Mexico City, and Guadalajara. Most Mexicans are of mixed Spanish and Indian descent, but about 30 percent are Indian—and millions still speak Indian languages in the southeast.
A 3,115-kilometer (1,936-mile) common border, commerce, and tourism link the world's largest Spanish-speaking country to its northern neighbor. Mexico is one of the world's largest oil producers—oil and gas provide a third of the government's revenue. Mexico exports oil to the U.S., which returns manufactured goods and foodstuffs. Agriculture remains an important employer. Mexico's system of communal farms, or ejidos, was reformed in the 1990s to promote private investment and large-scale agriculture. The North American Free Trade Agreement (NAFTA) makes Mexico highly dependent on exports to the U.S., and the downturn in U.S. business in 2001 resulted in little or no growth in the Mexican economy.
The nation is blessed with abundant minerals—notably silver, copper, sulfur, lead, and zinc—advanced technology, and a huge workforce. It profits from its maquiladora border industry: products are assembled at mostly U.S.-owned plants, then sent to the U.S. and elsewhere. The foreign plant owners gain from the lower cost of doing business in Mexico, and Mexicans gain jobs. However, many poor Mexicans try to cross the border for jobs in the U.S.—an estimated five million Mexican immigrants are in the U.S. illegally.
Mexico's declining birthrate promises some relief from the crushing pressure of its population. In 2000 Mexico became the 11th country in the world to have 100 million people—more than double its 1970 population of 48 million. With more than 19 million people, many living in barrio slums, Greater Mexico City is one of the world's largest urbanized areas. Tough environmental restrictions have been enacted to cope with increasingly dangerous levels of air and water pollution.