One thing that expats to the United States, especially from densely populated Europe, find difficult to comprehend is the sheer scale of the place.
At the risk of stating the blindingly obvious, the United States is enormous. In fact, the USA is so big that the entire European Union (all 28 member countries) could fit inside it, twice.
My new home state, California, is (by population at least) the largest state in the union. But how does it compare to my native United Kingdom?