The 3 most numerous ethnicities are Hispanics, African Americans, and Asian Americans of major U.S. ethnicities among states and within urban areas. Hispanics are clustered in the Southwest, African Americans in the Southeast and Asian Americans in the West.
Scientists like Einstein, Bethe, Fermi, Teller, and Bloch emigrated from "Germany" in order to escape persecution and pursue scientific research, since this took place during the rise of the Nazi Party, which was highly anti-Semitic.