The link to the book "Cowboys-Vaqueros" by Donald Gilbert y Chavez is updated here (old link above now invalid).

This account of the origins of the Cowboy is now hosted by the New Mexican Hispanic Culture Preservation League. It includes history, a glossary, brands, saddle images, etc. Each of the 12 chapters, in pdf, is separately linked. Or go directly to Chapter One- Chapter One

Read and enjoy.

Cowboys Vaqueros