Editing Keystone Service (section)

=== Through service ===
{{Amtrak Valley Forge}}
At its inception on May 1, 1971, Amtrak ran two through services on the line: the combined New York–Chicago ''[[Broadway Limited]]'' and New York–St. Louis ''[[Spirit of St. Louis (train)|Spirit of St. Louis]]'' (soon renamed ''[[National Limited (Amtrak train)|National Limited]]''), and the Pittsburgh–New York ''Duquesne'' (soon renamed ''[[Pennsylvanian (train)|Keystone]]''). The former train stopped only at Lancaster and Paoli between Harrisburg and North Philadelphia; it was intended for long-distance travelers between the East Coast and the Midwest rather than local passengers. The ''Duquesne''/''Keystone'' had one additional stop at Coatesville and was intended for medium-distance intercity travel.<ref name="tt19710501" />

Amtrak discontinued the ''Keystone'' on April 30, 1972, leaving the 600-series trains as the only local service along their route. The ''Broadway Limited'' and ''National Limited'' were split; they added local stops west of Harrisburg, but passengers from between Harrisburg and Philadelphia had to change trains at Harrisburg, Lancaster, Paoli, or Philadelphia to reach stops west of Harrisburg or north of Philadelphia.<ref name="sanders">{{Sanders-Heartland}}</ref>{{rp|64}} On October 28, 1973, Amtrak changed the weekday-only '''''Valley Forge''''' from a Philadelphia–New Haven local train to a Harrisburg–New York City train. It only made the same intermediate stops as the ''Keystone'', including no direct service to 30th Street Station.<ref>{{Cite book |url=http://www.timetables.org/browse/?group=19731028&item=0028 |title=All-America Schedules |date=October 28, 1973 |publisher=Amtrak |page=27 |via=Museum of Railway Timetables}}</ref> However, its introduction meant that through passengers no longer had to change at Philadelphia or rely on the ''Broadway Limited'', whose on-time performance had plunged to just 6.8% in 1973.<ref name="sanders" />{{rp|20}}

Additional local stops in Pennsylvania were later added. On May 19, 1974, Amtrak added weekend service on the ''Valley Forge'': a Saturday train from Harrisburg to Boston, and a Sunday train from Boston to Harrisburg.<ref name="baer1974" /> The weekend service ended on October 26, 1975.<ref name="baer1975" /> On October 28, 1979, Amtrak and SEPTA began the "Ardmore Connection": the ''Valley Forge'' began stopping at {{amtk|Ardmore}}, where a close connection could be made with a SEPTA Paoli–Philadelphia local train.<ref name="baer1979" /> On December 17, 1979, the westbound ''Valley Forge'' began stopping at 30th Street rather than bypassing it using the Pittsburgh Subway; however, it retained the Ardmore stop.<ref name="baer1979" /><ref>{{Cite book |url=http://www.timetables.org/browse/?group=19800203&item=0026 |title=National Train Timetables |date=February 2, 1980 |publisher=Amtrak |page=25 |via=Museum of Railway Timetables}}</ref>

The Washington sections of the ''Broadway Limited'' and ''National Limited'' originally split at Harrisburg and reached the Northeast Corridor via the [[Columbia and Port Deposit Railroad|Port Road Branch]]. The Washington section of the ''Broadway Limited'' was rerouted through Philadelphia on October 26, 1975; the ''National Limited'' followed suit on October 29, 1978.<ref name="sanders" />{{rp|41,62}} The ''National Limited'' was discontinued entirely on October 1, 1979; the state began funding the Pittsburgh–Philadelphia ''[[Pennsylvanian (train)|Pennsylvanian]]'' as a replacement on April 27, 1980.<ref name="sanders" />{{rp|75}}

[[File:Amtrak ACS-64 670 WB at Downingtown station.jpeg|thumb|left|Harrisburg-bound ''Keystone Service'' train at Downingtown in 2018, with locomotive at the rear of the train]]
At the same time, a pair of ''Clockers'', the westbound ''Keystone'' and eastbound ''Big Apple'', were extended to Harrisburg on weekends.<ref name="baer1980" /> They ran within an hour of the ''Valley Forge''{{'s}} weekday schedule; however, they ran to 30th Street and Suburban stations rather than only serving North Philadelphia.<ref>{{Cite book |url=http://www.timetables.org/browse/?group=19800427&item=0025 |title=National Train Timetables |date=April 27, 1980 |publisher=Amtrak |page=24 |via=Museum of Railway Timetables}}</ref> The ''Keystone'' was renamed ''Susquehanna'' on October 25, 1981.<ref name="tt19811025" /> The ''Big Apple'' and ''Susquehanna'' dropped the Suburban Station stop a year later, but continued to serve 30th Street.<ref>{{Cite book |url=http://www.timetables.org/browse/?group=19821031&item=0023 |title=National Train Timetables |date=October 31, 1982 |publisher=Amtrak |page=22 |via=Museum of Railway Timetables}}</ref> On October 30, 1983, the ''Pennsylvanian'' was extended to New York City, eliminating the transfer at Philadelphia (although it continued to stop at 30th Street).<ref>{{Cite book |url=http://www.timetables.org/browse/?group=19831030&item=0035 |title=National Train Timetables |date=October 30, 1983 |publisher=Amtrak |page=34 |via=Museum of Railway Timetables}}</ref> On January 12, 1986, the eastbound ''Valley Forge'' began serving 30th Street (as the westbound had for six years); this allowed it to effectively replace a canceled ''Keystone Service'' train (#600, the first morning eastbound) to serve commuters.<ref name="baer1980" /><ref name="tt19860427">{{Cite book |url=http://www.timetables.org/browse/?group=19860427&item=0026 |title=National Train Timetables |date=April 27, 1986 |publisher=Amtrak |pages=25–26 |via=Museum of Railway Timetables}}</ref>

Amtrak began operating the Atlantic City–Philadelphia ''[[Atlantic City Express (Amtrak train)|Atlantic City Express]]'' in 1989, and later extended it along several busy corridors in hopes of increasing ridership. On April 4, 1991, one daily ''Keystone Service'' round trip was extended to [[Atlantic City Rail Terminal|Atlantic City]] under the ''Atlantic City Express'' brand. Only a weekend round trip continued to be through-routed. The ''Atlantic City Express'' was discontinued on April 2, 1995; [[NJ Transit Rail Operations|New Jersey Transit]] [[Atlantic City Line]] trains continue to serve 30th Street Station.<ref name="waltzer">{{Cite web |last=Waltzer |first=Jim |date=October 6, 2005 |title=Waltz Through Time: An Express Derailed |url=http://www.atlanticcityweekly.com/news-and-views/50667032.html |archive-url=https://web.archive.org/web/20110707183728/http://www.atlanticcityweekly.com/news-and-views/50667032.html |archive-date=July 7, 2011 |website=[[Atlantic City Weekly]]}}</ref>