Dr. John Rector
The involvement of American merchants in the Chinese coolie trade which was at its height from 1850 to 1880 was inextricably linked to both the Peruvian guano trade and the growing demand for cheap labor in the United States. The discovery by English merchants of significant deposits of guano on the Chincha islands off of the coast of Peru in the early 1820's began a period of immense wealth as merchants realized the potential use of guano as fertilizer for European farmers.
Schultz, Austin. "American Merchants and the Chinese Coolie Trade 1850-1880: Contrasting models of human trafficking to Peru and the United States." Department of History seminar paper, Western Oregon University, 2011.