Pew Research Center looking at Hispanic trends has this fascinating graphic, with an interactive timeline of changes in the source of immigrants into America from 1850 through to 2013. See link below.
Must say I’m slightly surprised that America’s population in 1850 was just 23.2million. By 1900 it was 76 million, 1950 reaching 152 million, and 281 million by 2000, to be 316 million in 2013. Certainly true that America has been built by immigration.