Was looking on Wikipedia (not sure how credible it is), and saw that German is the largest white ancestry in the US with 16.5%. English was at 9.2%. I always thought English would be the by far majority due to America initially being colonized by England (I'm fairly certain I'm right here...)...
Was there any certain period in time where there was an influx of German immigrants to the US (maybe after WWI or WW2) that caused them to have the most prevalent white ancestry here?
Country of origin has been recorded for all legal U.S. immigrants since 1820. The numbers are presented by the Office of Immigration Statistics in the 2012 Yearbook of Immigration Statistics. I have copied the numbers for the UK, Ireland and Germany (note that Germany was only officially formed in 1871), and made a quick graph.
Note that German immigrants have rather consistently outnumbered U.K. immigrants (the exception being the first decades of the 20th century). I can speculate on the reasons for the fluctuations in the numbers, but I will leave that to the real historians.