Drawing on evidence that includes nearly half a million interviews conducted over a quarter of a century, Putnam shows how changes in work, family structure, age, suburban life, television, computers, women's roles, and other factors are isolating us from each other. We sign 30 percent fewer petitions than we did ten years ago. Membership in organizations -- from the Elks, Boy Scouts, and political parties, to the Knights of Columbus, P.T.A., and churches -- is falling. Ties with friends and relatives are fraying: we're 35 percent less likely to visit neighbors or have dinner with our families than we were thirty years ago. We watch ballgames alone instead of with our buddies.

A century ago, our means of connecting were at a low point after decades of urbanization, industrialization, and immigration uprooted us from our families and friends. That generation demonstrated a capacity for renewal by creating the organizations that pulled Americans together. Putnam shows how we can learn from them and reinvent common enterprises that will make us secure, productive, happy, and hopeful.