The Chicago, Indianapolis and Louisville Railway, also know as the Monon, commissioned famous railroad artist Howard Fogg to paint a number of images that the railroad released as a postcard series. The Pittsburgh & Lake Erie did the same and released their own line of Fogg image postcards. This is the Monon series showing both F and RS diesel units pulling freight and passenger trains. Printed on linen postcard stock by the renowned postcard publisher Curt Teich & Co. of Chicago, they were released in the early '50s with one of the cards in my collection postmarked 1953.
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