It was the standard light passenger locomotive of the USRA types, with a 4-6-2 wheel arrangement in the Whyte notation, or 2′C1′ in UIC classification.

1504 is one of seventy USRA Light Pacifics built by ALCO for the Atlantic Coast Line Railroad (ACL).

[13]: 7 [14] It was assigned to haul the ACL's premier passenger trains such as the Miamian, Florida Special, Palmetto Limited, Southland, South Wind and Dixie Flyer.

[14] In 2021, the locomotive was purchased by the U.S. Sugar Corporation (USSC) in Clewiston, Florida, where it is being restored to operating condition for use in excursion service on the South Central Florida Express shortline railroad as part of USSC's heritage tourist passenger train named the Sugar Express.

In 1960, the locomotive was purchased by Richard Jensen, who subsequently restored it to pull excursion trains on the Baltimore and Ohio Chicago Terminal Railroad (B&OCT).

5629 was refitted with a larger ex-Soo Line tender to pull long-distance excursions throughout the Chicago metropolitan area and the state of Indiana.

[19][a] In the early 1970s, Jensen was running into some financial trouble, due to legal issues with the C&WI and a loss of access to nearby railroads, and he lost all motivation to operate steam excursions.

5629 to the nearby Iowa Interstate Railroad (IAIS), but upon inspecting it to be moved, he discovered that it was vandalized during its time stored in Blue Island.

[8] Many groups, such as the Illinois Railway Museum, offered to purchase the locomotive for $15,000 and move it out of harm’s way, but Jensen declined and instead removed No.

5632-5634) constructed by the Baldwin Locomotive Works of Eddystone, Pennsylvania in November 1929, and it was delivered to the Grand Trunk Western Railroad (GTW) in 1930.

[24] The only difference from the USRA design is that the K-4-b class was equipped with an all-weather vestibule cab and an enclosed coffin feedwater heater.