North Side Main Line
E104833
The North Side Main Line was a historic elevated rapid transit route in Chicago that formed a key part of the early "L" system and later evolved into segments of today’s Red Line.
All labels observed (2)
| Label | Occurrences |
|---|---|
| North Side Main Line canonical | 19 |
| North Side main line | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T831974 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: North Side Main Line Context triple: [Addison station (CTA Red Line), formerRailwayLine, North Side Main Line]
-
A.
South Side Main Line
The South Side Main Line is a key elevated rapid transit corridor on Chicago's 'L' system that carries multiple Green Line services through the city's South Side.
-
B.
Dyre Avenue Line
The Dyre Avenue Line is a New York City Subway line in the Bronx operated by the IRT division, primarily serving the 5 train along a former New York, Westchester and Boston Railway right-of-way.
-
C.
Myrtle Avenue Line
The Myrtle Avenue Line is a New York City Subway line in Brooklyn and Queens, primarily served by the M train.
-
D.
Fulton Street Line
The Fulton Street Line is a major New York City Subway corridor in Brooklyn and Manhattan that carries IND services such as the A and C trains along Fulton Street.
-
E.
Jerome Avenue Line
The Jerome Avenue Line is a New York City Subway route in the Bronx, primarily served by the 4 train and running along Jerome Avenue from the Yankee Stadium area toward the northern end of the borough.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: North Side Main Line Target entity description: The North Side Main Line was a historic elevated rapid transit route in Chicago that formed a key part of the early "L" system and later evolved into segments of today’s Red Line.
-
A.
South Side Main Line
The South Side Main Line is a key elevated rapid transit corridor on Chicago's 'L' system that carries multiple Green Line services through the city's South Side.
-
B.
Dyre Avenue Line
The Dyre Avenue Line is a New York City Subway line in the Bronx operated by the IRT division, primarily serving the 5 train along a former New York, Westchester and Boston Railway right-of-way.
-
C.
Myrtle Avenue Line
The Myrtle Avenue Line is a New York City Subway line in Brooklyn and Queens, primarily served by the M train.
-
D.
Fulton Street Line
The Fulton Street Line is a major New York City Subway corridor in Brooklyn and Manhattan that carries IND services such as the A and C trains along Fulton Street.
-
E.
Jerome Avenue Line
The Jerome Avenue Line is a New York City Subway route in the Bronx, primarily served by the 4 train and running along Jerome Avenue from the Yankee Stadium area toward the northern end of the borough.
- F. None of above. chosen
Statements (31)
| Predicate | Object |
|---|---|
| instanceOf |
defunct railway line
ⓘ
elevated rapid transit line ⓘ historic transportation infrastructure ⓘ |
| cityServed |
Chicago
ⓘ
linked to:
City of Chicago
|
| country |
United States
ⓘ
linked to:
United States of America
|
| electrification | third rail ⓘ |
| evolvedInto |
Chicago "L" Red Line
ⓘ
linked to:
Red Line (Chicago "L")
|
| formedPartOf | early Chicago "L" network ⓘ |
| hasLineColorSuccessor | Red ⓘ |
| locatedIn |
Chicago
ⓘ
linked to:
Chicago, Illinois, United States
Illinois ⓘ United States ⓘ
linked to:
United States of America
|
| notableFor |
being a predecessor of the modern Red Line
ⓘ
forming a key part of the early Chicago "L" system ⓘ |
| openingDate | late 19th century ⓘ |
| operatedBy |
Chicago Rapid Transit Company
ⓘ
Chicago Transit Authority ⓘ |
| partOf |
Chicago "L" system
ⓘ
linked to:
Chicago "L"
|
| publicTransportSystem | Chicago "L" ⓘ |
| railwaySystem | Chicago Transit Authority ⓘ |
| region | Midwestern United States ⓘ |
| routeType | elevated railway ⓘ |
| servedArea |
Chicago North Side
ⓘ
linked to:
North Side of Chicago
|
| servedCity |
Chicago
ⓘ
linked to:
City of Chicago
|
| status |
historical
ⓘ
no longer used as a distinct named route ⓘ |
| structureType | elevated ⓘ |
| successorLine |
Red Line (Chicago Transit Authority)
ⓘ
linked to:
Red Line (Chicago "L")
|
| trackGauge | standard gauge ⓘ |
| transportationMode | rapid transit ⓘ |
| usedFor | urban passenger transport ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: North Side Main Line Description of subject: The North Side Main Line was a historic elevated rapid transit route in Chicago that formed a key part of the early "L" system and later evolved into segments of today’s Red Line.
Referenced by (20)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: North Side Main Line
subject linked to:
Red Line and Purple Line
subject linked to:
Belmont Red/Brown/Purple Line station
subject linked to:
Wilson Red/Purple Line station