These 20 Ten-Wheelers were built by ALCO-Rogers for the Chicago Southern Railroad between 1905 and 1907. When this company went bankrupt, 14 locomotives had not yet been delivered. Ten of these were purchased by Northern Pacific and designated class S-10. The remaining four went to other customers.
Eight of the Southern Pacific were retired between 1928 and 1933. Only 321 and 328 remained in use on branch lines. While 321 was scrapped in 1946, 328 ran for the last time in 1948. After being restored by the Minnesota Transportation Museum, it was operational from 1981 to 2001. Today it can be found at the Jackson Street Roundhouse in St. Paul, Minnesota.