Another book I perused recently is Carl Bridenbaugh's Vexed and Troubled Englishmen, 1590 - 1642. His conclusions are well summarized as follows (p. 25):
The extraordinary mobility of the people of the United States in the present century is customarily interpreted as a uniquely American phenomenon, but that this is far from so is made overwhelmingly clear to anyone who studies the local histories of seventeenth-century England. The beginnings of American mobility are in Stuart England.
As Bridenbaugh shows, in the fifty years before 1642, everything seemed to be going wrong in England -- politics, economics, religion. Their society was becoming more dynamic, but the forces of creative destruction are not always pleasant, and many Englishmen began to look elsewhere for new opportunities (pp 474-476):
... The ordinary man and woman found all these happenings disrupting and disturbing, and a very large minority of them came to think of themselves as supernumeraries of whom the land was weary. They were truly vexed and troubled Englishmen.
Literate and thinking persons among those who did not rule had many good and sufficient reasons for leaving the country; they lacked only the impetus or impulse to depart. In 1619 and for a decade thereafter, the doubts about England in the minds of men, which tended to propel them away from the island, were steadily re-inforced by the attactions of distant places rosily pictured in promotion tracts, enthusiastically preached about in sermons, and expansively elucidated in conversations with friends and by a certain class of subtle men. Those of the English who followed the western star were ambitious, energetic, intelligent (often educated), and venturesome members of the middle and lower orders of the most dynamic society in the Western World -- perhaps on the entire globe....
Master William implied a religious sifting of the Englishmen in the sermon quoted in the previous chapter on New England, but we may properly extend the sifting to other categories and to all of the settlers in the King's dominions in America in 1642. They were sifted socially because they were Englishmen who came almost entirely from the middle and lower ranks. They were sifted by religious beliefs and affiliations, whether Anglican, Puritan, or Roman Catholic. They were sifted by literacy in some degree and by education. They were further sifted by courage and hardihood, by physical vigor and energy, as well as by hopes, ambitions, and dreams about the future. Their world-view took in a wider range than that of those who stayed home. And all of this sifting was accomplished by the emigrants themselves and their children without the paternal hand of government, which guided all other colonial undertakings.
Whatever their reasons for leaving England -- a combination that differed with each individual -- and without any awareness of it, these ordinary men and women had together performed the most daring and portentous act of modern history when they succeeded in planting a new nation where none before had stood.
Yes, Americans are a crazy and hypomaniacal people...