What is the importance of the Crusades to the nonfiction book, An Indigenous Peoples’ History of the United States?

The author notes the Crusades as a major turning point in European history and as a precursor to colonialism. During the Crusades, European soldiers and mercenaries attacked and plundered Muslim cities, which concentrated a vast amount of wealth within a small portion of Europe’s population. Culturally, such concentration of wealth led to the establishment of land as private property and to a societal emphasis on wealth as an ethic in itself. Colonial and imperialistic ventures are directed by these motives towards wealth.