There were 11.9 million unauthorized immigrants living in the United States in March 2008. The size of the unauthorized population appears to have declined since 2007.
Most of the unauthorized population lives in families, a quarter has at least some college education and illegal workers can be found in many sectors of the US economy.
The undocumented population of the US now numbers nearly 11 million people, including more than 6 million Mexicans according to new estimates based on the most recent official data available.