Kentucky and the Illinois Central Railroad - Hardcoverby Clifford J. Downey (Author) The Illinois Central Railroad (ICRR) operated approximately 600 miles of mainline track throughout the Commonwealth of Kentucky, stretching from the Mississippi River to the central part of the state. In addition to Louisville, the state s largest city, the ICRR also served dozens of small towns. Kentucky s economy was built around coal mining and farming, and the ICRR played a major role in both industries. ICRR s coal