>>508403030 (OP)
Ancestry surveys in the US are flawed, and this is noted when you read the fine details of these surveys. Americans tend to state their ancestry as being the "most recent deviation from the norm" on these surveys. In other words, you're 95% English ancestry but you have one great great grandmother that was half-German? The person will state that they're of German ancestry. Or, you're 90% English ancestry, but you've got a family member up the line that has some Norwegian in them? They'll mark Norwegian on their survey, despite having nothing but English names throughout their family. This comes from the culture as it's seen to be cool or interesting to have an heritage that's different or interesting. But it is a studied and noted fact about the topic.
Also, there's the fact that many just mark their ancestry as being "American". This is overwhelming done by people of British stock: in particular Scottish, English, and Scots-Irish. This is really popularly done through those in Appalachia, the Mid-Atlantic, and Midwest.
So those with English and Scottish ancestry is grossly underrepresented on these surveys and data maps.
That's not to say there wasn't and isn't a large portion of the country that does have some German ancestry, but it's grossly overrepresented.