All major historical movements can be examined, not only in terms of conquests, battles and industry, but also in terms of the damage, alterations, and bio-population shifts these events left in their wake. Looking at the expansion of the West through the prism of ecological change is a particularly useful introduction to environmental history, because it is relatively recent, the variety of ecosystems is rich, and the effects have been dramatic and well documented.6-pages, bibliography lists 3 sources.