The Indian Wars were a series of conflicts between the US government and Native American tribes. These wars were often brutal and resulted in the death of thousands of Native Americans. The forced relocation of tribes, like the Trail of Tears, was also a devastating event that killed many.
The smallpox epidemic was another major factor in the decline of Native American populations. Since they had no immunity to the disease, it wreaked havoc on their communities. Some estimates suggest that up to 90% of some tribes were killed by the disease.