When the Twin Zephyrs began operating in 1936, they took 6-1/2 hours between Chicago and St. Paul, for an average speed of 66 mph. In 1940, however, the Burlington speeded up the westbound Morning Zephyr to just 6 hours, for an average speed of 71 mph–faster than today’s Acela over about the same distance between Boston and Washington. The eastbound Morning and both Afternoon Zephyrs took 6-1/4 hours.
Burlington moved its zephyrs around frequently. For this timetable, the Mark Twain Zephyr connected St. Louis with Kansas City, while that train’s original St. Louis-Burlington route was covered by the Pioneer Zephyr, and the Pioneer‘s original route between Kansas City and Lincoln was held by the Silver Streak Zephyr. For most railroads, the name went with the route, though the equipment may change; for Burlington’s original zephyrs, the name stuck with the trains whatever the changes in routes.