Internment of German Americans

Internment of German resident aliens and German-American citizens occurred in the United States during the periods of World War I and World War II. During World War II, the legal basis for this detention was under Presidential Proclamation 2526, made by President Franklin D. Roosevelt under the authority of the Alien Enemies Act. With the U.S. entry into World War I after Germany's unrestricted submarine warfare, German nationals were automatically classified as enemy aliens.

Source: Wikipedia — Internment of German Americans (CC BY-SA 4.0)