Immigration from Mexico to the United States has gone through four main periods. The first wave, occurring prior to World War II, consisted of agricultural workers recruited by private labor contractors, with the number of Mexican immigrants rising from 105,200 in 1900 to 624,400 in 1930. The Bracero program, from 1942 to 1964, ushered in the second wave, also consisting mostly of agricultural guest workers. The third, largely unauthorized wave began after the Bracero program was terminated and after 1965 changes to U.S. immigration law ended national-origin quotas and imposed the first numerical limits on Mexico and other Latin American countries. The majority of Mexican immigrants in this third wave were male, seasonal farm laborers who regularly traveled back and forth across the border. The passage of the Immigration Reform and Control Act of 1986 (IRCA) and subsequent investments in border security were a turning point, initiating the fourth wave of Mexican migration. IRCA legalized close to 3 million unauthorized migrants, including 2.3 million Mexicans, in return for tougher border enforcement and penalties for American employers who hired unauthorized workers. As crossing the border became more difficult, and as economic changes in the United States opened additional jobs to low-skilled foreign workers, immigrants began to settle permanently, bringing their families to live in the United States. Between 1990 and 2010 more than 7.5 million Mexican immigrants—many of whom were unauthorized—arrived.
More recently, Mexican immigration to the United States has begun to decline—marking at least a pause, and possibly an end to the fourth wave. Declining inflows appear to reflect the impact of the Great Recession, improved educational and economic opportunities in Mexico, and ever-tougher border enforcement.
