By 1915, the United States was the world's richest nation — and yet most Americans were dirt poor by today's standards. Adjusted for inflation, men's average wages were about a third of what full-time workers now earn. The average workweek in manufacturing hovered around 50 hours, and many employees worked a half day on Saturday. Less than a third of homes had electric lights. Less than a fifth of the adult population were high school graduates.

How we've changed.

Every so often, we need to take note. For all of today's pessimism, America's long-term trends are mostly positive. We tend to forget that and the parallel lessons. First, dramatic change is a constant; the notion that we're living in a period of exceptional upheaval is a shortsighted fiction. And second, America has a solid record of adapting to change, albeit with some setbacks and regrets.