The first part of what came to be called the Ninth Street Branch was the Philadelphia, Germantown and Norristown Railroad's line between Philadelphia and Germantown, which opened on June 6, 1832.
The Philadelphia and Reading Railroad, forerunner of the Reading Company, leased the PG&N on December 1, 1870.
The P&R's primary Philadelphia depot was then at Broad and Callowhill, but it began routing some trains to the PG&N's depot at Ninth and Green as well.

The Reading leased the North Pennsylvania Railroad in 1879, adding the North Pennsylvania's substantial network of suburban Philadelphia lines and what became the New York Branch–the North Penn's New York–Philadelphia line.
Also in 1879 the Reading constructed the Tabor Branch from Wayne Junction, where the PG&N's original line continued toward Germantown, to the North Penn's Bethlehem Branch at Tabor Junction.
This permitted the Reading to route New York-bound trains over the PG&N as well.
Finally, at the urging of the City of Philadelphia, the Reading consolidated its passenger options on the PG&N route.
The Reading constructed the Reading Terminal, a new elevated terminal at Twelfth and Market.
An elevated line connected the terminal to the existing line at Ninth and Green.
The extension opened on January 29, 1893.

The line north of Ninth and Green remained at street level and its grade crossings saw numerous accidents.
Again at the urging of the city, and after the route acquired the derisive sobriquet "Death Alley", the Reading elevated the entire branch.
Work began on October 3, 1907 and was completed on January 1, 1911.
During the late 1920s the Reading implemented a 12 kV 25 Hz overhead electrification on its Philadelphia commuter lines which originated from the Reading Terminal.
Electric service began on July 26, 1931.
The first part of what came to be called the Ninth Street Branch was the Philadelphia, Germantown and Norristown Railroad's line between Philadelphia and Germantown, which opened on June 6, 1832. The Philadelphia and Reading Railroad, forerunner of the Reading Company, leased the PG&N on December 1, 1870. The P&R's primary Philadelphia depot was then at Broad and Callowhill, but it began routing some trains to the PG&N's depot at Ninth and Green as well.
The Reading leased the North Pennsylvania Railroad in 1879, adding the North Pennsylvania's substantial network of suburban Philadelphia lines and what became the New York Branch–the North Penn's New York–Philadelphia line. Also in 1879 the Reading constructed the Tabor Branch from Wayne Junction, where the PG&N's original line continued toward Germantown, to the North Penn's Bethlehem Branch at Tabor Junction. This permitted the Reading to route New York-bound trains over the PG&N as well. Finally, at the urging of the City of Philadelphia, the Reading consolidated its passenger options on the PG&N route. The Reading constructed the Reading Terminal, a new elevated terminal at Twelfth and Market. An elevated line connected the terminal to the existing line at Ninth and Green. The extension opened on January 29, 1893.
The line north of Ninth and Green remained at street level and its grade crossings saw numerous accidents. Again at the urging of the city, and after the route acquired the derisive sobriquet "Death Alley", the Reading elevated the entire branch. Work began on October 3, 1907 and was completed on January 1, 1911. During the late 1920s the Reading implemented a 12 kV 25 Hz overhead electrification on its Philadelphia commuter lines which originated from the Reading Terminal. Electric service began on July 26, 1931.
Ninth Street Branch