Democracy in America, de Tocqueville.
Good choice.
I agree - Democracy in America was the first book that came to my mind. Although I think demographic changes have made it a little less relevant, it should be a good introduction to American society for another 20-30 years - until the demographics overtake the culture.
I second Democracy in America, de Tocqueville.
Good choice. The best choice, even though it's 180-odd years old.
Distant competitors might be Crevecoeur's Letters from an American Farmer and Benjamin Franklin's Autobiography.
At some point in history it got hard to write about "America" as a whole.
Maybe Henry James or Mark Twain or Hemingway or Fitzgerald had something to say in fiction about the American character.
For the closest thing to a modern Tocqueville maybe we have to go back to David Reisman's The Lonely Crowd.
Second that, too.