Partially built in 1892 and completed in 1910, the branch line served the Potomac Electric Power Company (PEPCO), the Washington Mill, and federal government buildings, but became obsolete as Georgetown's waterfront changed.

Ten years after the Chessie System bought the B&O in 1973, the railroad announced that it would ask the Interstate Commerce Commission to allow it to abandon the Georgetown Branch.

[5] At that time, the only customers were the General Services Administration, which used the railroad to bring coal to a heating plant at 29th and K streets, and a small building-supply company in Bethesda.

Railroad officials said they were losing money on the line and that it detracted from the scenery around the Washington Harbor development, of which Chessie was a part owner.

[7][8] Problems with the line were exacerbated after the Potomac River flood in November undermined about 75 feet of roadbed near Fletcher's Boathouse.

[15][16] The following year, the Montgomery County Council voted to build a trolley and bike trail along the Bethesda-Silver Spring section of the right-of-way.

[13] In 1991, advocates John Dugger and Henri Bartholomot helped secure federal funding through the Intermodal Surface Transportation Efficiency Act to develop the Maryland portion of the trail.

[22] With the right-of-way and funding secured, the groundbreaking for the trail was held on September 30, 1992, when Montgomery County leaders symbolically pried loose one of the railroad ties.

[33][34] It has benches, stone sitting walls, a curving pathway, a red metal pergola, bike racks, a repair station, a display with trail information, and a plaque to honor Potter.

There were also lawsuits over the ownership of the line; adjacent homeowners, the Chevy Chase Land Company, and Columbia Country Club all sued the county.

[43] On May 17, 1997, the Georgetown Branch Interim Trail opened from the east side of the 1910 Air Rights Tunnel in Bethesda to Stewart Avenue in Silver Spring.

[45] In June 2000, Montgomery County committed $1.3 million to repair the Rock Creek Trestle, which had been damaged by arson and fire, most notably in 1967, and open it for trail use.

Each iteration included plans to pave a parallel extension of the trail between Bethesda and Silver Spring and using the existing Air Rights Tunnel.

It went west on an unpaved, crushed-stone surface passing over Rock Creek on a trestle to Chevy Chase and then to Bethesda through the 800-foot-long Air Rights Tunnel.

Crossing into Washington, D.C., it then turns southeast, dropping down from the Palisades neighborhood over the C&O Canal on the Arizona Avenue Railway Bridge, and down to the banks of the Potomac.

It then runs between the Potomac and the C&O Canal, past Fletcher's Boathouse and the Foundry Branch Tunnel, into Georgetown to its terminus at the west end of Water Street NW.