Source: The 2008 data are from the US Census Bureau's 2008 American Community Survey. The 2000 data are from the Current Population Survey, March Supplement, 2000. All other data are from Gibson, Campbell and Emily Lennon, US Census Bureau, Working Paper No. 29, Historical Census Statistics on the Foreign-Born Population of the United States: 1850 to 1990, US Government Printing Office, Washington, DC. 1999. This report is available online.