The Illinois Central Railroad purchased its first "Mountain" type locomotives from the American Locomotive Company in 1923. This first order consisted of fifteen (road numbers 2400 through 2414) locomotives which had 28 x 28 cylinders, 73.5" drivers and a 230 psi boiler pressure. They exerted 58,138 lbs of tractive effort and weighed 362,500 pounds.

In 1925, the IC took delivery of twenty-five (road numbers 2415 through 2439) more,this time, from the Lima Locomotive Works and in 1926 another twenty (road numbers 2440 through 2459) came from ALCO. These forty-five locomotives were very similar to the fifteen received in 1923, except for an increase of 5,000 lbs in locomotive weight.

The Paducah, KY Shops of the Illinois Central built a total of 76 "Mountain" type locomotives between 1937 and 1943. The 2500 series were built at the IC Paducah shops from older IC 2-10-2 boilers originally built by Lima.

Number 2613 was used on the L&N Centennial between Louisville and Nashville on Oct 24, 1959. It also ran two excursions out of Louisville to Paducah on May 14, 1960 and to Dawson Springs on Oct 2, 1960. It was kept in the Paducah roundhouse and was in freight service in the Paducah area a few times. It was almost preserved when it was offered (for sale) to the Kentucky Railway Museum. However, the IRM declined the offer and the engine was scrapped. There are two surviving IC "Mountains", number 2500, at a park in Centralia, IL and number 2542 at the IC depot in McComb, MS.