The little band of Puritan emigres that left Southampton in 1620 to found a godly colony in Virginia (as the eastern seaboard of the North American continent was known then) carried with them the ideological seed-corn of a new nation. They were leaving England so that they could worship God in the way their conscience told them was right but in fact they were the forerunners of the greatest feat of nation-building in the early modern world. The vibrant...