Pebble in the Sky (Galactic Empire)

The third and final book in the Galactic Empire series, the spectacular precursor to the classic Foundation series, by one of history’s most influential writers of science fiction, Isaac Asimov
After years of bitter struggle, Trantor had at last completed its work—its Galactic Empire ruled all 200 million planets of the Galaxy . . . all but one. On a backward planet called Earth were those who nurtured bitter dreams of a mythical, half-remembered past when the planet was humanity’s only home. The other worlds despised it or merely patronized it—until a man from the past miraculously stepped through a time fault that spanned a millennium, living proof of Earth’s most preposterous claims.
Joseph Schwartz was a happily retired Chicago tailor circa 1949. Trapped in an incredible future he could barely comprehend, the unlikely time traveler would soon become a pawn in a desperate conspiracy to bring down the Empire in a twist of agony and death—a mad plan to restore Earth’s tarnished glory by ending human life on every other world.