Prior to skydark it was a wealthy nation that grew from humble beginings as a former colony of the British Empire. Over the centuries it shed itself of slavery after a bloody Civil War, and embraced manufacturing, and high technology. Several of its technological wonders including the Mat-Trans, Chrono sleep, space travel, and limited time travel.
During the second half of the 20th century the American nation engaged in a cold war with the Soviet Union, and its successor state Russia. This eventually flared up into the brief and dissasterous day known as skydark. Casualties were horrendous, with massive loss of life from nuclear explosions, and the resulting starvation and warfare over the remaining meager resources. Large stretches of land were left irradiated, and submerged under water, and unrecognizable from space. The nation itself ceased to exist after this date, although many small isolated colonies attempted to keep the spirit alive.
What remained after skydark was the Deathlands, where hope has died, but the will to survive continues on!