It very well may be German... When the Germans came over here, there was no "umlaut" (the 2 little dots above a vowel in certain words) in English... so the easiest way to communicate the sound of the vowel was to put an "e" after the vowel (vs having the umlaut over it).

Note my last name "Roeger" was "Roger" with 2 little dots over the o.

Krueger (if it's a German Surname) would have been Kruger with 2 little dots over the o.