Why did red cloud oppose railroad construction across the great plains?

Red Cloud opposed railroad construction across the Great Plains primarily because it threatened the sovereignty and way of life of the Lakota people. The expansion of railroads facilitated the influx of settlers and the further encroachment on Native American lands, disrupting their hunting grounds and traditional lifestyles. Additionally, he viewed the railroad as a tool for the U.S. government to assert control over Native territories, which fueled his resistance to the ongoing violations of treaties.