This must have really been something to see in 1939! The back of the postcard reads:
WESTINGHOUSE BUILDING - featuring the Time Capsule, the Singing Cascades, the Great Halls of Power, Science and Electrical Living, Elektro the Moto-Man and Sparko his pup, the Battle of the Centuries, the Microblitzkrieg, and many other outstanding Fair hits.
OMG! Time Capsule! Elektro! Sparko! This was the beginning of the future! Microblitzkrieg? That was the beginning of World War II.