Mount Vernon Seminary for Girls Historic District: This campus has been significant in both girls' education in DC and Naval history nationwide.

The 38.6-acre Mount Vernon Seminary for Girls campus includes 16 buildings, generally brick with Georgian Revival or simple Colonial Revival detailing. Six of these date to the period between 1916 to 1942, when the complex was first developed and used as the Mount Vernon Seminary for Girls, the first non-sectarian female boarding school in Washington, DC, whose curriculum was progressive for its time. The remaining ten date from the period between 1943 and 1952, when the U.S. Naval Communications Annex (NCA) used the property for cryptographic work and continued construction in a style that complemented the existing buildings. Here, Navy crypt analysis of coded German U-boat messages helped turn the tide of the North Atlantic sea campaign during World War II.

The campus currently operates as the Nebraska Avenue Complex for the Department of Homeland Security.

DC Inventory: May 26, 2016

National Register: August 10, 2016