The Union Pacific "M-10000" was the first American streamliner, beating the better-remembered Burlington "Pioneer Zephyr" to the punch. Featuring an early carbody design, the locomotive had huge air intakes at the front of the unit that gave it a "Teddy Roosevelt Clenching" look that became common with other early trains that followed (such as the Illinois Central's Green Diamond). The M-10000, Zephyr, and Diamond also shared another characteristic: the cars behind the locomotive rode on shared