Arlington has evolved since the end of World War I from a farming community into one of sprawling homes, large-scale retailing, and office buildings small to colossal. Connected to Washington by four bridges and three subway lines, the county is vital to the capital, providing office space to the federal government and housing to its employees. First the War Department, then Department of Defense and all military service headquarters were moved to the Pentagon, then numerous other government offices and bureaus moved to Arlington and nearby Virginia communities like Langley (home of the CIA) as they required larger quarters than were available in Washington. This trend continues. For the visitor, Arlington offers somber reflection at the nation's cemetery, a plethora of dining and lodging options, and easy access to the attractions of Washington.
Carved out of Fairfax County when the District of Columbia was created, Arlington was returned to Virginia along with the rest of the state's contribution in 1846, and until 1920 was the County of Alexandria. In the 19th century, members of the Custis family, including Martha Washington's first husband, had extensive land holdings in the area. Arlington was the name of the Custis family home that became the home of Robert E. Lee, now the Custis-Lee Mansion in Arlington Cemetery.