The Indiana Central Railway (IndC) and the Lawrenceburg and Upper Mississippi Railroad (L&UM) were so included shortly thereafter.
On March 2, 1885, the Indiana General Assembly passed legislation allowing for the incorporation of union railroad companies.
From July 1, 1915, through the end of 1922, another large construction project was undertaken to elevate the tracks over 18 feet (5.5 m) via earthen embankments, retaining walls, and bridges.
The other railroads operating in Indianapolis at the time no longer had any equity stake, but continued to pay rent to the IU for their joint use of the company's facilities.
At this time, the IU owned Indianapolis' Union Station (and its appurtenances) along with 1.769 miles (2.847 km) of main line trackage.
Finally, when Conrail was broken up and sold in 1999, the Indianapolis Union Railway became a part of CSX Transportation, which began operating it the next year.