In 1941 the War Department began building their headquarters, known as the Pentagon, in Arlington. The Pentagon was one of the first federal buildings constructed outside of downtown Washington. The Pentagon's 3.6 million square feet of office space took just over a year to complete at a cost of $75 million.

The unique pentagon shape of the building was chosen so that the building could fit between Arlington Memorial Drive, Arlington Memorial Bridge, National Cemetery, Arlington Ridge Road, and Fort Myer. Though this location was deemed unsuitable for the building, the pentagonal shape remained. The Pentagon's construction led to the destruction of the nearby Queen City African American community.


On land which had once been Arlington Tract Farms, the farming portion of the Freedman’s Village community, the Department of Agriculture created an expansive farm for testing new crops and farming techniques. Known as the Experimental Farm, this facility was created in 1913 between the Butler-Holmes and Johnson’s Hill’s communities. The farm provided Arlingtonians the opportunity to continue to work as farmers long after the region changed from rural to suburban. In 1940 the farm relocated to Maryland to make room for the War Department's building project, which would ultimately use other nearby land upon which to build the Pentagon.