[9][11][12][13] In May of that year, the tracks between Arlington Junction and Four Mile Run were doubled to allow for storing rush hour cars during the day.

[4] In 1903 they built a loop around the block bounded by King, Fairfax, Prince and Royal in Alexandria to allow trains in either direction to turn around.

[4] In 1905, to accommodate the construction of a new City Hall on the site of the Capital Traction Company's former power house, which had burned to the ground in 1897, the railway terminal was moved from 13 1/2 Street and E to 12th and D, NW.

At the end of 1920, the US Government cut a deal to finish the line and operate service on it, paying rent to the streetcar with an option to buy it.

In early 1930, it was announced that the line south of Alexandria, which had long been losing money, would be abandoned, scrapped and the land sold to the federal government.

By 1931 it was decided that the DC terminal and a portion of tracks for the Mount Vernon, Alexandria and Washington railway would need to be removed to make way for the project.

[30][31] For a brief time it operated as the Mount Vernon, Alexandria and Arlington railway, but it was granted permission to suspend service which it did on April 9 of that year.

After leaving Arlington Junction, trolleys on the Washington-Mount Vernon line continued south along the present route of S. Eads Street while traveling largely on the grade of a towpath on the west side of the defunct Alexandria Canal.

[37] After crossing Four Mile Run into present-day Alexandria, the trolleys continued to travel south along the present route of Commonwealth Avenue.

The lines' St. Elmo stations, located in Alexandria's present Del Ray neighborhood, gave travelers an opportunity to transfer between the railroads.

[39] The Mount Vernon line's trolleys then continued southward along Commonwealth Avenue until reaching King Street near Alexandria's Union Station.

They then turned again, traveled south on S. Royal Street and crossed Hunting Creek to enter Fairfax County on a 3,500 feet (1,067 m)-long bridge containing a concrete and steel center span and trestle.

After crossing Little Hunting Creek, they reached a turnaround loop on which they traveled to a terminal constructed near the entrance to the grounds of George Washington's home in Mount Vernon.

At Mount Vernon, when the electric railway began service, the estate's proprietors insisted that only a modest terminal be constructed next to the trolley turnaround.

They were afraid that the dignity of the site would be marred by unrestricted commercial development and persuaded financier Jay Gould to purchase and donate thirty-three acres outside the main gate for protection.

After leaving Arlington Junction, the Rosslyn branch traveled northwest along a route that was south of the future site of The Pentagon, crossed Columbia Pike and entered Mt.

However, after leaving the trolleys outside of the Sheridan Gate at the branch's Arlington station, visitors needed to ascend a steep hill to reach most of the Cemetery's well-known features and burial sites.

The track though Fort Myer was extended past the northwest entrance to Arlington National Cemetery to reach Penrose in 1900 and Nauck, just north of Four Mile Run, in 1901.

[81] A building at Arlington Junction – about 500 feet southwest of the current intersection of Army-Navy Drive and Eads – that served as a dispatcher's office, substation and passenger waiting room was removed in 1975.

[91] Originally constructed by the Washington, Arlington and Falls Church Railroad, the Nauck line (aka the Fort Myer or Green Valley line) of the Washington—Virginia Railway ran south from Rosslyn through Fort Myer to an initially lightly developed area in South Arlington near Four Mile Run.

The line then turned to the southwest and crossed the northern boundary of the Arlington Reservation and Fort Myer near today's Wright Gate.

Work paused and during the Spanish American War Camp Russel A. Alger was established past the western terminus of the rail line.

The line then traveled northeast through Fairfax County a short distance east of Chain Bridge Road, crossed another branch of Accotink Creek, passed through Oakton, and reached the town of Vienna.

Freight and work cars usually bypassed the station and avoided reversing by turning from the northeast direction to the southeast on the third leg of the wye.

[115] After entering Ballston, the line passed a complex containing a car barn, rail yard, workshops, electrical substation and general office that the Washington, Arlington and Falls Church Railway had built in 1910 at Lacey near the present intersection of North Glebe Road (now Virginia State Route 120) and Fairfax Drive.

[118] Beginning in 1906, travelers on the North Arlington and Rosslyn branches and the Nauck line could transfer at the Rosslyn terminal to the Great Falls and Old Dominion Railroad (later the Great Falls Division of the W&OD Railway), which ran a "bridge car" that crossed the Potomac River into Georgetown on the Aqueduct Bridge.

After leaving Clarendon, trolleys on the South Arlington branch largely followed the future routes of Washington Boulevard and Southgate Drive.

The car barn was built in 1910, when the line was double-tracked, to replace one that was located several blocks east at the northwest corner of N. Stafford Street and Fairfax Drive.

The branch traveled from Clarendon southeast along the present route of Washington Boulevard and crossed the western boundary of the Arlington Reservation and Fort Myer.

The branch then traveled east along the present route of Southgate Road, now immediately south of Henderson Hall, Fort Myer and Arlington National Cemetery.