Excerpts from Books and Wikipedia
"Over the next few years gold-seekers, known as 'forty-niners,' after the year 1849, came swarming in to pan every stream and mine every piece of land.… From 1850, California flourished. By 1860, the population increased from 14,000 to 380,000. Cities were founded and roads and railroads were built. The gold rush opened up the American West, and discoveries of gold and silver similarly influenced the settlement of Nevada, Colorado, Oregon, Montana, and the Dakotas." [Furtado: 1001 Days] "California was the first state to be settled by peoples from all over the world. . . . To those who lived through it, the well-named 'Rush' seemed a dramatic example of the individualism, instability, rapid change, eager pursuit of wealth, and preoccupation with speed characteristic of America in their lifetime. It also testified to the power of hope, and hope built the United States." [Howe: What Hath God Wrought, p. 821-2]