One who attempts to look beneath the surface cannot accept this easy method of treatment.

Beneath the surface new tendencies develop long before they demand recognition; an institution may be decaying long before its weakness is apparent.

The American Revolution began not with the Stamp Act but at least a century earlier, as soon as the settlers realized that there were three thousand miles of sea between England and the rude country in which they found themselves; the Civil War began, if not in early Virginia, with the "Dutch Man of Warre that sold us twenty Negars," at least with Eli Whitney and his cotton gin.
Nevertheless, certain dates or short periods seem to be flowering times.
Apparently all at once a flood of invention, a change of methods, a difference in organization, or a new psychology manifests itself.

And the decade of the Civil War does serve as a landmark to mark the passing of one period in American life and the beginning of another; especially in agriculture; and as agriculture is the basic industry of the country it follows that with its mutations the whole superstructure is also changed.
The United States which fought the Civil War was vastly different from the United States which fronted the world at the close of the Revolution.

The scant four million people of 1790 had grown to thirty-one and a half million.