Let me make a post of actual substance on here:
This trip has really driven home to me how much of a federal republic the United States is. I went from Portland, Maine to New Orleans, Louisiana in two days. Two areas with very different economies, topographies, ethnicities and climates. There aren't many places in the world where two such different societies would share political union, but they do here. It's amazing that the whole thing works as well as it does.