Unrepeatable...........................?

The century of revolution in the United States after the Civil War was economic, not political, freeing households from an unremitting daily grind of painful manual labor, household drudgery, darkness, isolation, and early death.  Only one hundred years later, daily life had changed beyond recognition.  Manual labor jobs were replaced by work in air-conditioned environments, housework was increasingly performed by electric appliances, darkness was replaced with light, and isolation was replaced not just by travel, but also by color television images bringing the world into the living room.  More important, a newborn infant could expect to live not to age forty-five, but to age seventy-two.  The economic revolution of 1870 to 1970 was unique in human history, unrepeatable because so many of its achievements could only happen once.

-Robert J. Gordon,  The Rise and Fall of American Growth:  The U.S. Standard of Living since the Civil War