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The Illinois Central Railroad's No. 1 was the railroad's only 4-6-4 "Hudson" type locomotive and the only 4-6-4 in North America built for freight service. It was rebuilt in the railroad's own shops from 2-8-4 "Berkshire" No. 7038 in 1937 as an experiment to haul fast freight trains, which were growing too large for 4-6-2 "Pacific" types and required more speed than the road's 2-8-2 locomotives could manage.
The experiment was not successful. The locomotive proved prone to slipping, because its factor of adhesion was very low; in simple terms it was too powerful for its ability to grip the rails. John L. McIntyre, the road foreman of engines at Clinton, Illinois where the locomotive was assigned during the 1938–1939 period, made some modifications to the locomotive, including to the weight equalization across the locomotives' wheels and to reduce the cylinder diameter from 27 to 24 inches (686 to 610 mm). The latter was to reduce the starting tractive effort to a level the locomotive's grip on the rails could handle. The improvements were successful, but not to the degree that the railroad ordered any further conversions.
In 1945, the locomotive was renumbered 2499 and assigned to passenger service between Louisville, Kentucky and Fulton, Kentucky. It was retired from service in 1949 and soon after scrapped.
