1640s: The Puritans believed in their mission to establish a model community for the Protestant world.

1850s: America had developed an ideology of "manifest destiny" that held that the prosperous expansion of Americans across the continent was inevitable and ordained, and implied that the country was destined to become a great global power.

Today: America's global power seems both assured with the splitting of the Soviet Union, and a thing of the past with the rise of countries like Japan and Germany to economic power.

1640s: The colonists, though not clearly provoked, fought with the Narraganset Indians against the Pequot Indians, at one point killing seven hundred Pequot men, women, and Children.

1850s: Native land claims had all but been eliminated east of the Mississippi with President Jackson's removal of the "five civilized tribes" in the late 1830s. Their bitter march to Oklahoma is...