History

• When the U.S. Border Patrol was created in 1924, the law defined "illegal alien" and labeled undocumented workers as fugitives. Prior to that time, the United States welcomed Mexican citizens without restrictions.
  
  

General Requirements

• A Mexican citizen must get a visa to legally enter the United States. Usually qualified family members sponsor the immigrant. A qualified family member is a spouse, parent (if the immigrant is a child under 21 years) or a child (21 years and over) who is a United States citizen or permanent resident. An employer may also sponsor the immigrant.
  
  

Procedure for Residents

• A Mexican immigrant who is already in the United States requests a green card by filing an adjustment of status form with U.S. Citizenship and Immigration Services.
  
  

Procedure for Nonresidents

• A Mexican citizen with an immigrant visa number may apply for consular processing at a U.S. Consulate.
  
  

Additional Fact

• The number of visas available is limited. According to "The New York Times," however, Mexican immigration was down by 25 percent in the year ending in August 2008.