Every Fourth of July, I like to remind myself what an astonishing experiment America is. Certainly, it was an experiment in 1776 when the Founders took an unprecedented step toward giving citizens the right to “Life, Liberty, and the pursuit of Happiness.” But it’s still an experiment now. 

There is no country on earth that is simultaneously as big, as free, as diverse, as developed. The state historian of California once told me that lawmakers there deal with third-world problems and first-world expectations. Through every generation, the United States has gotten successively bigger, more free, more diverse, more developed. It is a unique, real-time test of how much liberty, equality, and self-government the human race can manage. And how America has managed that test has mattered for the human race. The US president isn’t hailed as the “leader of the free world” just because of the nuclear briefcase. 

This Fourth of July, the question seems as poignant as ever: Can America grow yet bigger, even more free, diverse, and prosperous? That history is ours to write.