Modes of Entry for the Unauthorized Migrant Population

From the Pew Hispanic Center

Nearly half of all the unauthorized migrants now living in the United States entered the country legally through a port of entry such as an airport or a border crossing point where they were subject to inspection by immigration officials.

As much as 45% of the total unauthorized migrant population entered the country with visas that allowed them to visit or reside in the U.S. for a limited amount of time. Known as "overstayers," these migrants became part of the illegal population when they remained after their visas had expired.

Another smaller share of the unauthorized migrant population entered the county legally from Mexico using a Border Crossing Card, a document that allows short visits limited to the border region, and then violated the terms of admission.

The rest of the unauthorized migrant population, somewhat more than half, entered the country illegally. Some evaded customs and immigration inspectors at ports of entry by hiding in vehicles such as cargo trucks. Others trekked through the Arizona desert, waded across the Rio Grande or otherwise eluded the U.S. Border Patrol which has jurisdiction over all the land areas away from the ports of entry on the borders with Mexico and Canada.

The Pew Hispanic Center has previously estimated that there are between 11.5 and 12 million unauthorized migrants in 2006. The calculations reported in this fact sheet suggest that roughly 4.5 to 6 million or 40 to 50% of the total entered the country legally through ports of entry. Of them, some 4 to 5.5 million entered with nonimmigrant visas, mostly as tourists or business visitors, and another 250,000 to 500,000 entered with Border Crossing Cards.