In 1868, Arlington was part of Alexandria County, but Rosslyn was already emerging as a transportation hub. From a map dated November 16, 1868:
The Town of ROSSLYNN is located immediately opposite GEORGETOWN at the Southern terminus of the Aqueduct Bridge and has been laid out by the "Alexandria Canal Rail Road and Bridge Company" for the purpose of making it a thriving place, in view of the important Rail Road and other interests to be centered there. It is contemplated to make the Aqueduct Bridge the main Rail Road connection between the North and South, a Turnpike Road to Falls Church, a Rail Road to Alexandria, and a branch to the Loudon and Hampshire Raid Road to connect with Rail Roads to be brought through Georgetown are among the enterprises soon to be inaugurated. It is also the intention to have the Street Cars from Washington cross the Aqueduct to Rosslynn. The Town Plats include good business property: Fine Residence lots, and a number of magnificent sites for Suburban Villas.Today Rosslyn is a transportation leader with a hub of multi-user trails, metro lines, and roads. Rosslyn's transportation leadership has deep historical roots.