Construction on the building then known as Union Station began in early 1895 under the architectural direction of Waddy Butler Wood.
 The superintendent and chief engineer of the Capital Traction Company, D.S. Carll, was in charge of the construction.
Before construction of the Car Barn, the two streets were joined by a steep hillside that carried 36th Street.
Large amounts of earth were excavated—80,000 cubic yards (61,000 m³) in total—resulting in the sharp cliff that exists today.
Adjacent to the Car Barn are a set of stairs commonly known as the "Exorcist steps" and a large retaining wall, which were built at the time the Car Barn was constructed, to connect M and Prospect Streets.
The steps are so named as they provided the location for the scene in the 1973 horror film The Exorcist where the priest is thrown down the stairs to his death.

The building's construction was opposed by the next-door resident of the Prospect House, who furnished affidavits by prominent architects stating that blasting from the construction was damaging her house; this led to court-ordered supervision of the blasting in 1894.
After the Car Barn's construction, the large edifice obstructed the view of the Potomac River and Virginia from homes on Prospect Street, including the well-known cottage of E. D. E. N. Southworth.
For this reason, some considered it a "desecration" of the local scenery.

The three-story, 180-by-242-foot (55 by 74 m) building was opened on May 27, 1897, containing offices for the several tenant trolley companies and waiting rooms that were decorated with red oak wainscot panelling, ornate iron stair railings, and stuccoed ceilings.
The exterior was designed in the Romanesque Revival style.
Its tower, which reached a height of 140 feet (43 m), contained an elevator that shuttled passengers between the terminals.
Many of the building's decorations reflect its original function.
The pediment facing M Street reads "Capital Traction Company" and contains three decorative flywheels.

The M Street-facing first floor served the Washington and Georgetown Railroad.
The second and third floors were connected with steel trestles to allow for trolleys coming across the Potomac River from Rosslyn, which served Washington, Arlington, Falls Church, and were projected to serve the Great Falls and Old Dominion Railroad.
The roof, which was level with Prospect Street, was used by the Metropolitan Railroad and had a covered walkway for passengers to get from the elevator to Prospect street.

The station operated as Washington's only cable car trolley terminal for less than a year.
Almost immediately after opening, the Car Barn was converted to operate the new electric streetcars.
The Virginia lines never made use of the terminal and the Metropolitan Railroad did not use the station to the extent intended.
It intended to place storage tracks on the roof of the building, but never did.
Construction on the building then known as Union Station began in early 1895 under the architectural direction of Waddy Butler Wood.  The superintendent and chief engineer of the Capital Traction Company, D.S. Carll, was in charge of the construction. Before construction of the Car Barn, the two streets were joined by a steep hillside that carried 36th Street. Large amounts of earth were excavated—80,000 cubic yards (61,000 m³) in total—resulting in the sharp cliff that exists today. Adjacent to the Car Barn are a set of stairs commonly known as the "Exorcist steps" and a large retaining wall, which were built at the time the Car Barn was constructed, to connect M and Prospect Streets. The steps are so named as they provided the location for the scene in the 1973 horror film The Exorcist where the priest is thrown down the stairs to his death.
The building's construction was opposed by the next-door resident of the Prospect House, who furnished affidavits by prominent architects stating that blasting from the construction was damaging her house; this led to court-ordered supervision of the blasting in 1894. After the Car Barn's construction, the large edifice obstructed the view of the Potomac River and Virginia from homes on Prospect Street, including the well-known cottage of E. D. E. N. Southworth. For this reason, some considered it a "desecration" of the local scenery.
The three-story, 180-by-242-foot (55 by 74 m) building was opened on May 27, 1897, containing offices for the several tenant trolley companies and waiting rooms that were decorated with red oak wainscot panelling, ornate iron stair railings, and stuccoed ceilings. The exterior was designed in the Romanesque Revival style. Its tower, which reached a height of 140 feet (43 m), contained an elevator that shuttled passengers between the terminals. Many of the building's decorations reflect its original function. The pediment facing M Street reads "Capital Traction Company" and contains three decorative flywheels.
The M Street-facing first floor served the Washington and Georgetown Railroad. The second and third floors were connected with steel trestles to allow for trolleys coming across the Potomac River from Rosslyn, which served Washington, Arlington, Falls Church, and were projected to serve the Great Falls and Old Dominion Railroad. The roof, which was level with Prospect Street, was used by the Metropolitan Railroad and had a covered walkway for passengers to get from the elevator to Prospect street.
The station operated as Washington's only cable car trolley terminal for less than a year. Almost immediately after opening, the Car Barn was converted to operate the new electric streetcars. The Virginia lines never made use of the terminal and the Metropolitan Railroad did not use the station to the extent intended. It intended to place storage tracks on the roof of the building, but never did.
Georgetown Car Barn