Racial segregation in the United States is the segregation of facilities, services, and opportunities such as housing, medical care, education, employment, and transportation in the United States along racial lines. The term mainly refers to the legally or socially enforced separation of African Americans from whites, but it is also used with regard to the separation of other ethnic minorities from majority mainstream communities. While mainly referring to the physical separation and provision of separate facilities, it can also refer to other manifestations such as prohibitions against interracial marriage (enforced with anti-miscegenation laws), and the separation of roles within an institution. Notably, in the United States Armed Forces up until 1948, black units were typically separated from white units but were nevertheless still led by white officers.