1900s
In 1907, the Market Street El was opened from 69th St to 15th St. One year later, the line was extended eastward to 2nd St through an underground portal at 13th St. The extention would turn onto Chestnut St. Later, another extention was made to South St.
1920s
Later in 1922, a second branch of the Market St El was erected north of 2nd St to Bridge-Prat becomming the Frankford El.
1950s
During construction in 1955, 36th, and 34th Sts were closed and reopened. 40th, 36th and 32nd Sts were replaced with underground stations 40th, 34th and 30th Sts. One year later, skip stop operations were implemented.
1970s
In 1977, Market-Frankford's Fairmount Station was closed due to the construction of the I-95 and later replaced with its current successor Spring Garden Station.
1990s
13 years later in 1990, 2nd St and Spring Garden switched to all stop stations with 34th St becoming an all stop station in 1994.
2000s
Some time later in 2003, Bridge-Pratt Station was rebuilt into Frankford terminal being rebranded as Frankford Transportation Center. Four years later, 46th St becomes an all stop service station.
2010s
The 2010's was a time of renaming and rebranding. In 2010, 13th/Juniper was renamed simply to 13th St Station with 5th St Station being renamed to Independence Hall in 2015. Three years later, Margaret-Orthodox was renamed to Arrot Transportation Center.
2020s
Two years later in 2020, skip stop service was eliminated from the system.
