[1] Its fixed five-car consist was also the end of an era; the popularity of the early streamliners was their undoing, because the trains could not be lengthened or shortened to handle varying loads.

Wartime in 1943 added an extra 15 minutes to the schedule to cope with traffic congestion, but the train was otherwise unchanged.

On September 29, 1946, with the full dieselization of all Chicago-St.Louis passenger service, the Green Diamond was changed to train Nos.

Unsurprisingly, the trainset was withdrawn from service on February 28, 1947, being replaced by a new Green Diamond, an E-unit-hauled streamliner with regular lightweight cars.

It re-entered service on April 27, 1947, as the Miss-Lou (MISSissippi-LOUisiana) between Jackson, Mississippi, and New Orleans, Louisiana, operating as Trains 27 and 28.