At the middle of the nineteenth century the two trails were quite distinct in personnel, if that word may be used.
The Santa Fe Trail showed Spanish influences; that of the Platte Valley remained far more nearly American.
Thus far the frontier had always been altering the man who came to it; and, indirectly, always altering those who dwelt back of the frontier, nearer to the Appalachians or the Atlantic.

A new people now was in process of formation--a people born of a new environment.

America and the American were conceiving.

There was soon to be born, soon swiftly to grow, a new and lasting type of man.

Man changes an environment only by bringing into it new or better transportation.