St. Louis & Parsons RPO with RMS ellipse - Superb cancel

The St. Louis & Parsons Railway Post Office (RPO) was a vital mail-sorting route operated by the Missouri-Kansas-Texas (M-K-T) railroad, commonly known as "The Katy". This route connected the major hub of St. Louis, Missouri, to the significant division point and shop complex in Parsons, Kansas. - Grade 1 card