The Chicago, Indianapolis & Louisville that emerged from bankruptcy and a thirteen-year receivership in 1946 was one sick pup. Its equipment was worn out; its newest steam locomotives dated from the 1920s, over a third of its freight cars were fit only for scrap, and the road's passenger fleet dated largely from World War I—only four passenger cars were all-steel. Worse, its physical plant was deteriorated; modern (1940s) steam power could not have operated on the road's flimsy tracks and trestles even if management had been able to afford it. The road had missed out almost entirely on the wartime surge of traffic as a result, and now that the war was over the traffic count would have been hard to find with a microscope. The Monon only operated a single passenger train out of  Chicago (which split at Monon to serve both of the road's southern terminals at Louisville and Indianapolis). Contrast that with competitor Pennsy's offering of three trains a day each way between Chicago, Indianapolis, and Louisville—the slowest of which was a full two hours faster than the Monon's solitary offering.

Enter John W. Barriger III. A professional railroader, a visionary, and an unabashed railfan, he set about to rebuild the Monon. The aging steam power was kicked out the door as fast as new diesels could be obtained; the Monon had completely dieselized by 1949. The right-of-way was upgraded with new rail and new bridges, where necessary. New freight cars were ordered, and Barriger vowed to run his new express freight trains on schedule even if there wasn't a single revenue car between the locomotive and the caboose. On the passenger front, Barriger was faced with a two-year backlog for new equipment from the three major builders. But a little investigation turned up a treasure trove of surplus U.S. Army hospital and troop cars in excellent condition, mostly wartime production from ACF. The Monon purchased them for a ridiculously low price and set about rebuilding them into modern streamlined passenger equipment. One of the fruits of this labor was the new equipment and name for Monon's train number 5 and 6—the Thoroughbred—and a new schedule which was competitive with the best that Pennsy had to offer.

Barriger succeeded in saving the Monon as a company; it remained a relatively prosperous regional railroad until it was finally acquired by and merged into L. & N. in 1971. However, once the Barriger era ended in 1952 the Monon's passenger service would begin to slip away. By the end of 1959 all service between Chicago and Indianapolis had ended and only the Thoroughbred remained in operation. It would continue to soldier on for another eight years—but on September 30, 1967 the Thoroughbred and scheduled Monon passenger operation would make its last run.