Mexicans have a long history of working and living in the USA. Migration is one of the most important linkages between North America’s two most populous countries. The Mexican diaspora in the USA is an integral part of both Mexican and US society. Each year roughly 250 million legal border crossings are made, about half by Mexicans. A much smaller number, perhaps a few hundred thousand, cross the border illegally despite US efforts to tighten border controls. The Mexican communities on either side of the border are very closely linked.
As of 2008 over 31 million Mexicans lived in the USA (see graph). This is more than one fifth of all Mexicans anywhere and a larger number than in any single Mexican state. Almost 19 million Mexican-Americans were born in the USA of Mexican parentage; these have always outnumbered migrants.
Roughly 10% of everyone born in Mexico now lives in the USA. This figure was only 5% as recently as 1990 and only 1.4% in 1970. Migrating Mexicans are as likely to move to the USA as within Mexico. Clearly, in recent decades, an increasing number of Mexicans have chosen to live in the USA.
[Extract from chapter 27 of Geo-Mexico: the geography and dynamics of modern Mexico]