Various "anti-miscegenation" state laws are passed prohibiting the marriage, cohabitation, and sexual relations of white people and African-Americans, and in many states also between Asians and white people, and Indigenous people and African-Americans.

Between 1913 and 1948, 30 out of the 48 states will pass and enforce such laws. While anti-miscegenation laws are often regarded as a Southern phenomenon, most Western and Plains states also enact them during this period. Although anti-miscegenation amendments are proposed in the U.S. Congress in 1871, 1912–1913, and 1928, a nationwide law against racially-mixed marriages will never be enacted.