Down this old winding trail into the greatest valley of all the world, and beyond that valley out into the Spanish country, moved steadily the adventurers whose fathers had but recently crossed the Appalachians.

One of the strongest thrusts of the American civilization thus entered the cattle-range at its lower end, between the Rio Grande and the Red River.
In all the several activities, mining, freighting, scouting, soldiering, riding pony express, or even sheer adventuring for what might come, there was ever a trading back and forth between home-staying men and adventuring men.

Thus there was an interchange of knowledge and of customs between East and West, between our old country and our new.

There was an interchange, too, at the south, where our Saxon civilization came in touch with that of Mexico.
We have now to note some fundamental facts and principles of the cattle industry which our American cattlemen took over ready-made from the hands of Mexico.
The Mexicans in Texas had an abundance of small, hardy horses of African and Spanish breed, which Spain had brought into the New World--the same horses that the Moors had brought into Spain--a breed naturally hardy and able to subsist upon dry food.

Without such horses there could have been no cattle industry.