Facilities and services such as housing, healthcare, education, employment, and transportation have been systematically separated in the United States based on racial categorizations. Notably, racial segregation in the United States was the legally and/or socially enforced separation of black people from white people, as well as the separation of other ethnic minorities from majority 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,, and the separation of roles within an institution. The U.S. Armed Forces were formally segregated until 1948, as black units were separated from white units but were still typically led by white officers.