It cared nothing whatever for the Indian tribes.

War, instant and merciless, where it meant murder for the most part, was set on foot as soon as white touched red in that far western region.
All these new white men who had crowded into the unknown country of the Plains, the Rockies, the Sierras, and the Cascades, had to be fed.

They could not employ and remain content with the means by which the red man there had always fed himself.

Hence a new industry sprang up in the United States, which of itself made certain history in that land.

The business of freighting supplies to the West, whether by bull-train or by pack-train, was an industry sui generic, very highly specialized, and pursued by men of great business ability as well as by men of great hardihood and daring.
Each of these freight trains which went West carried hanging on its flank more and more of the white men.