SCOTTISH-AMERICAN NAMES (nameset 16)
1.7% of American population
As with the Irish nameset, there are quite a few English and Welsh names mixed in with the Scottish nameset. I've deleted many of those, although there is a good deal of unavoidable overlap (Black, for instance, is a common Scottish and English name).
Sources that I used include:
16 Scottish-American first names.txt
16 Scottish-American names.txt