Eye on United States at 250

The United States celebrates 250 years of independence on Saturday. Two and a half centuries ago, the early settlers of this land broke free from the yoke of colonial rule. In the centuries that followed, waves of people of the globe arrived on these shores, their lives intertwining, their cultures colliding and ultimately fusing together on this vast new continent. Adam Tooze is a leading British historian currently teaching at Columbia University's History Department in the US. As a non-American living in the country, viewed from an international and historical vantage point, what does he make of America's 250-year history and its present-day reality?