The Illinois Central rebuilt one of its 2-8-4 "Berkshires" (number 7038) to be a 4-6-4 "Hudson" in its own shops and gave it road number 2499.

When first rebuilt this new "Hudson" had 27 x 30 cylinders, 73.5 drivers, a 270 psi boiler pressure, and a tractive effort of 68,350 pounds. The tractive effort was too great for the weight on the drivers, so this locomotive was very slippery. After extensive tests in 1937, it was decided that the cylinder diameter would be reduced by three inches. After this modification number 2499 was assigned to passenger service.