Mexico’s relationship with the United States began with the settlement of Anglo-Americans in northern Mexico in the 1820s. Hostilities between the two governments and groups of citizens, particularly in what is now the southwestern United States, escalated into the Mexican American War of 1846–8. The Treaty of Guadalupe Hidalgo officially ended the war between the two nations, although portions of the treaty remain in dispute over 150 years after its signing. Relations between Mexico and the United States and its citizens have fluctuated from cordial to violent.

On the macroscopic level, the relationship of the United States with Mexico in the last fifty years is a neo-colonial one. Mexico’s material and human resources are continually utilized by the United States, on both sides of the border. This unequal status and exploitation began in 1848, and violent eruptions, such as the Mexican Revolution of 1910, have resulted. The Border Industrialization Program in the 1960s, and the North American Free Trade Agreement in the 1990s, have further eroded the Mexican economy and government and created domestic instability At the beginning of the twenty-first century issues such as the United States’ militarization of the border in “wars” on drugs and undocumented immigration continue the legacy of distrust between the two nations.

At the microscopic level, the 1848 treaty awarded the northern half of Mexico to the United States, and, with it, the people on those lands. Personal and political ties remained between Mexicans living on both sides of the border and distinct cultural variations emerged. Mexicans and Mexican culture (and United States citizens and their culture) continue to move back and forth across the Rio Grande, suggesting the border between the two countries is more political than social. Despite at times hostile relations between the two governments, personal and community relations continue to thrive. Mujer a Mujer, a binational network of female workers discussing shared labor concerns, demonstrates the strength and utility of such ties.

One area which transcends both nations is the ecosystem they share. Since the 1960s, devastating water, air and soil pollution has affected all living organisms in both countries. The Coalition for Justice in the Maquiladoras is one example of a simultaneously grassroots and transnational organization formed to address shared concerns, such as the environment. This type of relationship between the United States and Mexico will necessarily increase as the number of Mexicans rises, both south and north of the border. The Chicano/Chicana population is one of the fastest growing in the United States. They have made Los Angeles, CA the second-largest Mexican city, suggesting the complexity of United States-Mexican relations in the future.