According to the Census Bureau's annual American Community Survey, a tight labor market and recession caused the first decline in foreign-born U.S. residents since 1970.  The contraction of the construction industry, previously an engine of growth, provided fewer opportunities for immigrants from foreign countries, particularly Mexico.  According to the Wall Street Journal, The number of Mexicans living in the U.S. fell to 11.4 million last year, a decline of 300,000. Mexico is the leading country of origin of immigrants to the U.S., accounting for one-third of all foreign-born U.S. residents.  Read more in Conor Dougherty and Mariam Jordan's interesting article that includes interactive graphics and photos.