sabine55 on 3/1/2012 1:52:12 PM:
From a 1937 Official Railway Guide: it shows all the Katy passenger train time-tables, but none of the trains had a number over 100, except one, a mixed (passenger & freight) train on a short branch between Dallas & Denton, TX (No. 471 and 476). The main line out of St. Louis to & fromTexas passenger trains were No. 2,4,6,8 and 1,3,5,7. No. 409 might have been the number on the front of the engine (the engine no.). MKT stood for Missouri-Kansas-Texas Lines or Katy Lines for short.