Yet that was not all of it. The new republic not only had thirteen separate subdivisions; it also had territories—first the untracked, almost wholly unsettled domain then known as the Northwest, a bit later the tremendous stretches of the Louisiana Purchase. The established communities along the seaboard were already beginning to throw off new communities in the open country beyond the Alleghenies, and this process obviously would continue. So while the new states were setting up their own governments and framing a central government to handle national affairs, it was also necessary to find the means by which entire new states could be created and brought into the national organization.

Thus with the unending westward expansion there was a steady creation of new, self-governing units. This went forward on what Mr. Nichols calls a do-ityourself basis, and it had profound effects on the whole national structure. What might have turned into “a unitary empire stretching endlessly westward and governed from the east” became instead a self-modifying system that was constantly expanding. There was a constant development of new patterns of democratic behavior, taking place not in Washington but in remote and scattered communities.

This put a high premium on the capacity to compromise. It also meant that there was unending experimentation; and indeed the whole concept of creating and operating frontier communities as a sort of training ground for the creation of new states was, as Mr. Nichols sees it, “one of the most inspired inventions of the American political genius.” It kept the American Leviathan from becoming ossified, and in the author’s words: “It was to be one of the important instruments that maintained experimentation in developing the capacity for self-government in the midst of the nation’s spectacular expansion in wealth and power. It gave elasticity to an organism that might otherwise have become rigid.”

Nevertheless, there were problems. Perhaps the country was growing too fast. Acquisition of Louisiana itself put an enormous strain on the machinery of government. When this was followed, a little more than a generation later, by the break-through to the Pacific and the swallowing of the immense land mass that ran from Texas to California, it began to be clear that the country had expanded more rapidly than its capacity to govern. The process of physical growth had, of course, brought the values that come from frequent self-renewal, but some sort of limit had been reached and passed. The Leviathan was becoming extraordinarily complex, and by the i86o’s the nation had somehow outgrown the pattern originally devised. A vast political reorganization was due. It was time to rebuild; and the tragedy was that very complex cultural and economic differences—following the great fault-line that divided the land between slavery and free-soil areas—made it impossible for men to get on with the rebuilding in a peaceable manner. The old genius for compromise had disappeared. What we got, at last, was the Civil War.