Dome cars have their earliest beginnings dating back to the late 19th century,
but these early designs were not successful and it was not until the streamliner
era that the car truly came of age. It was in the mid-1940s Cyrus Osborn, vice
president and general manager of General Motors’ Electro-Motive Division
conceived what he dubbed a Vista Dome car built from a Budd Company coach,
which featured a second-floor solarium for an unprecedented 360 degree view
of the surrounding landscape. By the 1950s dome cars were all of the rage and
almost all named trains across the country carried some type or design of them.

(American-Rails.com)