These cars were seen on railroads across North America. Harriman cars were developed during the time of Edward Henry Harriman, who controlled the Chicago & Alton Railroad, the Union Pacific, the Southern Pacific, the Illinois Central, the Central of Georgia, the Pacific Mail Steamship Company, Wells Fargo Express Company, and directed the development of the "Common Standard Specifications" among the Associated Lines. This set of specifications allowed parts to be shared across all Harriman-controlled railroads, allowing economical bid prices due to the sheer size of standardized orders, standardized part inventories and methods for car repair.

These cars were designed with the a distinctive arched roof and diamond underframe crossbearers. The Arched Roof construction handled rainy weather better than clerestoy design - once lighting and ventilation problems were solved. Non-Harriman Arched Roof cars, while similar, had fished-belly underframes developed by Pullman Mfg. Co. and copied by others.  Some of these 60-ft cars remained in use until the advent of Amtrak while others became maintenance-of-way cars.

The Illinois Central had a large batch of round roof 64-ft* baggage-express cars. While once part of the Harriman empire, their designs were never Common Standard designs which UP and SP adopted. All IC cars had fishbelly frames and non-flushed ends. These IC cars lasted well into the late 60s and often found mixed wtih lightweight passenger equipment. IC No. 580 was assigned to carry sacks of US mail as well as express shipments. It was a 1918 Pullman product, Class P579: 64'-8" Baggage, weighing in at 58 tons. * 64-ft 8-in as measured over the coupler face, 60-ft 10-in over the end sills.

• Extra fine details,
• crisp paint & printing,
• sliding baggage doors,
• nicely weighted for the runner,
• new adjustable draft gear and 6-wheel truck with 36" metal wheelsets,
• MT Couplers.