From 1921 to 1927 , Washington , D.C. was withdrawn from Third Corps Area and established as the District of Washington .
Third Corps Area variously headquartered at Fort McHenry and Fort Howard in Baltimore , Maryland and included Pennsylvania , Maryland , District of Columbia and Virginia .
From 1921 to 1927 , District of Columbia     was withdrawn from Third Corps Area and established as the District of Washington .
Third Corps Area variously headquartered at Fort McHenry and Fort Howard in Baltimore , Maryland and included Pennsylvania , Maryland , District of Columbia and Virginia .