As the nineteenth century drew to a close, people living in coastal Louisiana noticed that local rodents called muskrats were rapidly increasing and quickly becoming pests by digging up crops and into levees. Property owners soon demanded their elimination, but to the ire of many, Louisiana officials chose to develop a market for muskrat fur and protect its supply through management laws. The state sought the cooperation of trappers in order to maintain global demand, but when nutria were released alongside the muskrat, the ecological balance of the marsh was permanently altered. Muskrats shrank back into obscurity, and trappers struggled to embrace the nutria as a substitute. This thesis will trace the Louisiana muskrat industry's development starting with its rise in the 1890s, continuing through its years as a leading furbearer, and ending with its replacement by the nutria in the 1960s.