5 million persons had both parents born in Germany; and 6 million persons had at least one parent born in Germany.[25] German immigrants had not been prohibited from becoming naturalized United States citizens and many did so. The large number of German Americans of recent connection to Germany, and their resulting political and economical influence, have been considered the reason they were spared large-scale relocation and internment.

Shortly after the Japanese strike on Pearl Harbor, some 1,260 German nationals were detained and arrested, as the government had been watching them.[26] Of the 254 persons not of Japanese ancestry evicted from coastal areas, the majority were ethnic German.[27] During WWII, German nationals and German Americans in the US were detained and/or evicted from coastal areas on an individual basis. Although the War Department (now the Department of Defense) considered mass expulsion of ethnic Germans and ethnic Italians from the East or West coast areas for reasons of military security, it did not follow through with this. The numbers of people involved would have been overwhelming to manage.[28]