Roos means rose, and veld is the Dutch equivalent of English field. But is rosefield a likely compound? Roses do not grow in masses except in nurseries, and the nurseryman does not speak of his rozenveld but will call it his rozentuin (rose garden) or rozenperk (rose bed). I cannot believe, therefore, that Roosevelt means rosefield.
The fact of the matter is that most Americans don't know much about their ancestors. Of one hundred randomly selected adults, how many do you suppose could give the maiden names of all of their four great-grandmothers, even if you gave them a few months to look up the data?
