I was born in the midst of the Great Depression, when no one could imagine the revolutionary technological advances that we now take for granted. Innovations in countless fields have transformed society and radically improved individual well-being, especially for the least fortunate. Every American’s life is now immeasurably better than it was 80 years ago.

What made these dramatic improvements possible was America’s uniquely free and open society, which has brought the country to the cusp of another explosion of life-changing...