SC&S = South Chicago & Southern
SL&IC was a subsidiary of the SC&S, which was a subsidiary of Pennsy. It looks like SC&S/SL&IC owned the northern track and B&OCT/C&CT owned the southern track. I have seen some comments that the two tracks were shared and ran as a double track route similar to the C&O and Erie arrangement between Griffith and State Line. (C&O owned the eastern track and Erie owned the western track. But in railfan photos you will see that both railroads did right-hand running on that route.)
|Bob Lalich posted|
Here is a USGS topo map from 1900. There are a number of interesting railroad historical details. East Chicago had been promoted in the late 1800s as an industrial center with rail access to all trunkline RRs via the Chicago & Calumet Terminal RR/Chicago Terminal Transfer RR. PRR subsidiary SC&S built a joint line with the C&CT from Clarke Station west to the Illinois state line - the State Line & Indiana City. Clarke Station was also a junction with the Wabash and EJ&E predecessor Chicago Lake Shore & Eastern. The Indiana Harbor Canal is shown but was still in the planning stage. Inland Steel didn't begin construction at Indiana Harbor until 1901. Construction of USS Gary Works had not begun either and NYC predecessor Lake Shore & Michigan Southern and the B&O crossed at Miller rather than Indiana Harbor.
|Bob Lalich commented on a posting|
And the SC&S had a subsidiary that built/owned the line from Pine Jct to State Line - State Line & Indiana City. PRR referred to the line as "the SLIC". Those initials are seen in many old maps and drawings. Here is an example.
|Calumet Junction (source)|
|Clarke Junction (source)|
State Line & Indiana City - a subsidiary of the SC&S - built a line from State Line Jct to Clarke Jct at the same time as the Chicago & Calumet Terminal RR built a parallel line. It was agreed to operate the two tracks as a double track railroad. The north track belonged to the SL&IC, the south track was owned by C&CT. C&CT reorganized as Chicago Terminal Transfer, went bankrupt, and was acquired by the B&O and reorganized as B&OCT.