Detailed data and the underlying micro data can be found at;

http://www.census.gov/population/foreign/

Two sources of information are:

Current Population Survey Data on the Foreign-Born Population

Detailed tables on the foreign-born population in the United States from the Current Population Survey shown by a wide range of characteristics including age, sex, marital status, employment status, occupation, industry, income, earnings, poverty status, household type, size and tenure, and metropolitan status

http://www.census.gov/population/foreign/data/cps.html

American Community Survey Data on the Foreign-Born Population

http://www.census.gov/population/foreign/data/acs.html