The U28C was developed by General Electric from the U25C, with a slight increase in power of 300 hp (224 kW). A passenger-hauling variant, the U28CG, was also produced for the Atchison, Topeka and Santa Fe Railway.
GE produced 71 U28C locomotives, not including ten U28CG passenger variants for the Santa Fe:
Ex-Union Pacific No. 2804 is preserved at the Museum of Transportation in St. Louis, Missouri. The rear of the locomotive has been cutaway to show the inner workings of a diesel locomotive.